resolveTo a resolver in additionalResolvers

[sarathkcm]

Season's greetings!

I am trying to extend schema of a type to add a new field following this guide - https://the-guild.dev/graphql/mesh/v1/schema-extensions#batch-delegation-array-batching

I need to use batching since in one query itself there will be a lot of sub queries made for the extended field .

However since the query for this extended field doesn't conform to the assumptions (input argument is a CSV instead of array and the order of the returned results is not guraranteed) I wanted to wrap it into a new query which conforms to the required signature and assumptions.
I used additionalTypeDefs in the mesh to extend the query and additionalResolver in the hive gateway to add the implementation (args transformation and sorting)

However when querying this field, I get an error saying context[additionalResolvers.sourceName][additionalResolvers.sourceFieldName]..... not found.

I realize that additional resolvers don't have any source name, and also the resolver is not available in the context during the execution, All other queries and mutations in each subgraph are available in the context, just not the ones added using additionalTypeDefs and additionalResolvers. That's what the error message probbaly refers to.

Is this the the expected/accepted behaviour? If so, how do I use batching with resolveTo directive with an API that doesn't conform to the expectations?