I'm in a similar situation. I want to replay LeafGreen and ultimately transfer the Pokemon over to HeartGold and beyond in an easier way than six at time with the original cartridge. So, I'm looking at playing the GBA game on my phone like you described.
From what you've described this looks like it would help a lot. But... how do I get the 3gpkm out of the save file in the first place so that I can run that batch?
I'm on a Mac, so if not Mac-native then ideally a Wine-compatible solution would be preferred. I'm already family with PokeGen, but that's not for Gen III.
Thanks,
