Sorry, but I think you're losing me
slow down and try to phrase what you say a little better.
I think the Gist of this is that you want final fantasy II on your Retron5,
but you don't need to make another patch, Demiforce already made one,
and It will work if you get it attached to a proper FF II ROM.
Retron5 can play gameboy advance right?
well google Final Fantasy I & II: Dawn of Souls rom
and you should be good to go no patching required.