I'm sorry but I don't even see anywhere in startzpool.bat where the number of gpus is specified (my apologies, I don't really do batch files myself at all, so not sure entirely what to look for)
-SelGPUEWBF '0 1' -SelGPUCC '0,1'
0 and 1 are GPUs. If you have six
-SelGPUEWBF '0 1 2 3 4 5' -SelGPUCC '0,1,2,3,4,5'