diff --git a/src/closyr/ops/modify.clj b/src/closyr/ops/modify.clj
index 9bf373e..8e17acc 100644
--- a/src/closyr/ops/modify.clj
+++ b/src/closyr/ops/modify.clj
@@ -234,27 +234,29 @@
   "A coll whose random element is the number of modifications to apply in succession"
   (->>
     []
-    (concat (repeat 60 1))
-    (concat (repeat 40 2))
-    (concat (repeat 25 3))
-    (concat (repeat 20 4))
-    (concat (repeat 19 5))
-    (concat (repeat 18 6))
-    (concat (repeat 17 7))
-    (concat (repeat 16 8))
-    (concat (repeat 15 9))
-    (concat (repeat 14 10))
-    (concat (repeat 13 11))
-    (concat (repeat 12 12))
-    (concat (repeat 11 13))
-    (concat (repeat 10 14))
-    (concat (repeat 9 15))
-    (concat (repeat 8 16))
-    (concat (repeat 7 17))
-    (concat (repeat 6 18))
-    (concat (repeat 5 19))
-    (concat (repeat 4 20))
-    (concat (repeat 3 21))
-    (concat (repeat 2 22))
-    (concat (repeat 1 23))
+    (concat (repeat 40 1))
+    (concat (repeat 30 2))
+    (concat (repeat 20 3))
+    (concat (repeat 18 4))
+    (concat (repeat 16 5))
+    (concat (repeat 15 6))
+    (concat (repeat 14 7))
+    (concat (repeat 13 8))
+    (concat (repeat 12 9))
+    (concat (repeat 11 10))
+    (concat (repeat 10 11))
+    (concat (repeat 9 12))
+    (concat (repeat 8 13))
+    (concat (repeat 7 14))
+    (concat (repeat 6 15))
+    (concat (repeat 5 16))
+    (concat (repeat 4 17))
+    (concat (repeat 3 18))
+    (concat (repeat 2 19))
+    (concat (repeat 1 20))
+    ;; (concat (repeat 3 21))
+    ;; (concat (repeat 2 22))
+    ;; (concat (repeat 1 23))
+    ;; (concat (repeat 1 24))
+    ;; (concat (repeat 1 25))
     vec))
diff --git a/src/closyr/symbolic_regression.clj b/src/closyr/symbolic_regression.clj
index 8941756..54f7c41 100644
--- a/src/closyr/symbolic_regression.clj
+++ b/src/closyr/symbolic_regression.clj
@@ -329,7 +329,7 @@
   [msg]
   (log/info "~~~ Restarting experiment! ~~~")
   (update-plot-input-data msg)
-  true)
+  :restart)
 
 
 (defn- check-gui-command-and-maybe-park
@@ -339,20 +339,18 @@
     :as   run-args}]
   (let [[{:keys [new-state] :as msg} ch] (alts!! [sim-stop-start-chan] :default :continue :priority true)]
     (when (and msg (not= msg :continue))
-      (if (= :stop new-state)
-        :stop
-        (if (= :restart new-state)
-          (restart-with-new-inputs msg)
-          (do
-            (log/info "~~~ Parking updates due to Stop command ~~~")
-            (let [{:keys [new-state] :as msg} (<!! sim-stop-start-chan)]
-              (if (= :stop new-state)
-                :stop
-                (if (= :restart new-state)
-                  (restart-with-new-inputs msg)
-                  (do
-                    (log/info "~~~ Resuming updates ~~~")
-                    nil))))))))))
+      (case new-state
+        :stop :stop
+        :restart (restart-with-new-inputs msg)
+        :pause (do
+                 (log/info "~~~ Parking updates due to Stop command ~~~")
+                 (let [{:keys [new-state] :as msg} (<!! sim-stop-start-chan)]
+                   (case new-state
+                     :stop :stop
+                     :restart (restart-with-new-inputs msg)
+                     :start (do
+                              (log/info "~~~ Resuming updates ~~~")
+                              nil))))))))
 
 
 (defn- ->run-args
@@ -479,7 +477,7 @@
       (log/info "Running with logging every n steps: " (:log-steps run-config))
 
       (assoc this :ga-result init-pop
-             :iters iters
+             :iters-to-go iters
              :start-ms start)))
 
 
@@ -487,7 +485,7 @@
     [this]
     (let [{:keys [iters log-steps]} run-config
           population  (:ga-result this)
-          iters-to-go (:iters this)]
+          iters-to-go (:iters-to-go this)]
       (binding [ops/*log-steps* log-steps]
         (if (zero? iters-to-go)
           (assoc this :status :done :result {:iters-done       (- iters iters-to-go)
@@ -495,20 +493,22 @@
                                              :next-step        :wait})
           (let [{scores :pop-scores :as ga-result} (ga/evolve population)]
             (ops/report-iteration iters-to-go iters ga-result run-args run-config)
-            (assoc this :ga-result ga-result :iters (next-iters iters-to-go scores)))))))
+            (assoc this :ga-result ga-result :iters-to-go (next-iters iters-to-go scores)))))))
 
 
   (next-state
     [this]
     (let [{:keys [iters initial-phenos initial-muts use-gui?]} run-config
-          iters-to-go   (:iters this)
-          population    (:ga-result this)
-          should-return (and use-gui? (check-gui-command-and-maybe-park run-args))]
-      (if (and use-gui? should-return)
-        (if (= :stop should-return)
+          iters-to-go         (:iters-to-go this)
+          population          (:ga-result this)
+          should-return-state (and use-gui? (check-gui-command-and-maybe-park run-args))]
+      (if (and use-gui? should-return-state)
+        (case should-return-state
+          :stop
           {:iters-done       (- iters iters-to-go)
            :final-population population
            :next-step        :stop}
+          :restart
           {:iters-done       (- iters iters-to-go)
            :final-population population
            :next-step        :restart})
@@ -517,7 +517,7 @@
 
   (run-iteration
     [this]
-    (let [{iter-status :status iters-to-go :iters ga-result :ga-result
+    (let [{iter-status :status iters-to-go :iters-to-go ga-result :ga-result
            done-result :result
            :as         res} (solver-step this)]
       (if (= :done iter-status)
@@ -530,7 +530,7 @@
 
   (end
     [this {:keys [next-step] :as return-value}]
-    (print-end-time (:start-ms this) (- (:iters run-config) (:iters this)) next-step)
+    (print-end-time (:start-ms this) (- (:iters run-config) (:iters-to-go this)) next-step)
     return-value))
 
 
@@ -676,16 +676,18 @@
 
 
 (defn- run-app-with-gui
-  []
-  (run-solver
-    {:initial-phenos (ops-init/initial-phenotypes 50)
-     :initial-muts   (ops-init/initial-mutations)
-     :iters          100
-     :use-gui?       true
-     :max-leafs      ops/default-max-leafs
-     :use-flamechart false
-     :input-xs-exprs example-input-xs-exprs
-     :input-ys-exprs example-input-ys-exprs}))
+  ([]
+   (run-app-with-gui {:use-flamechart false}))
+  ([{:keys [use-flamechart]}]
+   (run-solver
+     {:initial-phenos (ops-init/initial-phenotypes 50)
+      :initial-muts   (ops-init/initial-mutations)
+      :iters          100
+      :use-gui?       true
+      :max-leafs      ops/default-max-leafs
+      :use-flamechart use-flamechart
+      :input-xs-exprs example-input-xs-exprs
+      :input-ys-exprs example-input-ys-exprs})))
 
 
 (def ^:private ^:dynamic *is-testing* false)
@@ -723,4 +725,5 @@
 (comment (macroexpand-1 `(log/info "Hello")))
 (comment (log/info "Hello"))
 (comment (run-app-without-gui))
+(comment (run-app-with-gui {:use-flamechart true}))
 (comment (run-app-with-gui))
diff --git a/test/closyr/symbolic_regression_test.clj b/test/closyr/symbolic_regression_test.clj
index 2518987..02a1ecb 100644
--- a/test/closyr/symbolic_regression_test.clj
+++ b/test/closyr/symbolic_regression_test.clj
@@ -5,7 +5,10 @@
     [closyr.ops :as ops]
     [closyr.ops.common :as ops-common]
     [closyr.ops.initialize :as ops-init]
-    [closyr.symbolic-regression :as symreg]))
+    [closyr.symbolic-regression :as symreg])
+  (:import
+    (java.awt
+      GraphicsEnvironment)))
 
 
 (alter-var-root #'symreg/*is-testing* (constantly true))
@@ -202,77 +205,79 @@
 
 
 (deftest can-run-experiment-gui:start-restart-stop
-  (binding [ops/*print-top-n* 1]
-    (testing "gui can start and restart experiments; NOTE: do not run this while in headless mode, eg on CI"
-      (with-redefs-fn {#'symreg/config->log-steps (fn [_ _] 500)}
-        (fn []
-          (let [control-process (go
-                                  (<! (timeout 200))
-
-                                  (is (put! symreg/*sim-stop-start-chan*
-                                            {:new-state          :start
-                                             :input-data-x       [0 1 2 3 4]
-                                             :input-data-y       [1 3 6 18 8]
-                                             :input-iters        200
-                                             :input-phenos-count 500}))
-
-                                  (<! (timeout 100))
-                                  (is (put! symreg/*sim-stop-start-chan*
-                                            {:new-state :pause}))
-                                  (<! (timeout 100))
-                                  (is (put! symreg/*sim-stop-start-chan*
-                                            {:new-state :start}))
-                                  (<! (timeout 100))
-                                  (is (put! symreg/*sim-stop-start-chan*
-                                            {:new-state :pause}))
-                                  (<! (timeout 100))
-
-                                  (is (put! symreg/*sim-stop-start-chan*
-                                            {:new-state          :restart
-                                             :input-data-x       [0 1 2 3 4]
-                                             :input-data-y       [1 13 16 8 8]
-                                             :input-iters        1500
-                                             :input-phenos-count 500}))
-
-                                  (<! (timeout 100))
-
-                                  (is (put! symreg/*sim-stop-start-chan*
-                                            {:new-state          :restart
-                                             :input-data-x       [0 1 2 3 4]
-                                             :input-data-y       [1 13 16 8 8]
-                                             :input-iters        5
-                                             :input-phenos-count 5}))
-
-                                  (<! (timeout 100))
-
-                                  (is (put! symreg/*sim-stop-start-chan*
-                                            {:new-state          :restart
-                                             :input-data-x       [0 1 2 3 4]
-                                             :input-data-y       [11 3 6 18 8]
-                                             :input-iters        300
-                                             :input-phenos-count 400}))
-
-                                  (<! (timeout 100))
-
-                                  (is (put! symreg/*sim-stop-start-chan*
-                                            {:new-state :stop}))
-
-                                  (<! (timeout 100))
-
-                                  (is (put! symreg/*gui-close-chan* :close-please))
-                                  (is (put! symreg/*sim->gui-chan* :next))
-                                  true)]
-
-            (symreg/run-solver
-              {:initial-phenos (ops-init/initial-phenotypes 20)
-               :initial-muts   (ops-init/initial-mutations)
-               :input-xs-exprs symreg/example-input-xs-exprs
-               :input-ys-exprs symreg/example-input-ys-exprs
-               :iters          20
-               :use-gui?       true})
-
-
-            (is (= (<!! control-process) true))))))))
+  (when (not (GraphicsEnvironment/isHeadless))
+    (binding [ops/*print-top-n* 1]
+      (testing "gui can start and restart experiments; NOTE: do not run this while in headless mode, eg on CI"
+        (with-redefs-fn {#'symreg/config->log-steps (fn [_ _] 500)}
+          (fn []
+            (let [control-process
+                  (go
+                    (<! (timeout 200))
+
+                    (is (put! symreg/*sim-stop-start-chan*
+                              {:new-state          :start
+                               :input-data-x       [0 1 2 3 4]
+                               :input-data-y       [1 3 6 18 8]
+                               :input-iters        200
+                               :input-phenos-count 500}))
+
+                    (<! (timeout 100))
+                    (is (put! symreg/*sim-stop-start-chan*
+                              {:new-state :pause}))
+                    (<! (timeout 100))
+                    (is (put! symreg/*sim-stop-start-chan*
+                              {:new-state :start}))
+                    (<! (timeout 100))
+                    (is (put! symreg/*sim-stop-start-chan*
+                              {:new-state :pause}))
+                    (<! (timeout 100))
+
+                    (is (put! symreg/*sim-stop-start-chan*
+                              {:new-state          :restart
+                               :input-data-x       [0 1 2 3 4]
+                               :input-data-y       [1 13 16 8 8]
+                               :input-iters        1500
+                               :input-phenos-count 500}))
+
+                    (<! (timeout 100))
+
+                    (is (put! symreg/*sim-stop-start-chan*
+                              {:new-state          :restart
+                               :input-data-x       [0 1 2 3 4]
+                               :input-data-y       [1 13 16 8 8]
+                               :input-iters        5
+                               :input-phenos-count 5}))
+
+                    (<! (timeout 100))
+
+                    (is (put! symreg/*sim-stop-start-chan*
+                              {:new-state          :restart
+                               :input-data-x       [0 1 2 3 4]
+                               :input-data-y       [11 3 6 18 8]
+                               :input-iters        300
+                               :input-phenos-count 400}))
+
+                    (<! (timeout 100))
+
+                    (is (put! symreg/*sim-stop-start-chan*
+                              {:new-state :stop}))
+
+                    (<! (timeout 100))
+
+                    (is (put! symreg/*gui-close-chan* :close-please))
+                    (is (put! symreg/*sim->gui-chan* :next))
+                    true)]
+
+              (symreg/run-solver
+                {:initial-phenos (ops-init/initial-phenotypes 20)
+                 :initial-muts   (ops-init/initial-mutations)
+                 :input-xs-exprs symreg/example-input-xs-exprs
+                 :input-ys-exprs symreg/example-input-ys-exprs
+                 :iters          20
+                 :use-gui?       true})
+
+
+              (is (= (<!! control-process) true)))))))))
 
 
 (deftest derive-log-steps