Dumping Sintax GBA Bootlegs

[RibShark]

Right now the dumper fails on Sintax GBA Bootlegs (in particular the bootleg I have is Rayman IV), reading only up to 0x201, with the rest of the ROM being filled with 00.
@tzlion told me this:

basically it relies on the GBA BIOS boot routine somehow and without that being run it just will lock out reads
the later ones will also lock you out if you read from certain rom locations
those are the ones that dont work on a DS
because i guess the DS menu does some read to figure out if a cart is present & it doesnt like that

Any idea if this could be adapted to dump such games?