Thanks for your response.
Oh, I found pointers from the "The 65535 pokemon" a couple of years ago. Do they seem right? It looks like people were able to edit past 440 after all.
And I'm making a Touhoumon hack, and I'm planning on adding a bunch of extra forms in the future. I already filled up 25 slots with just Dark Touhoumon, and I didn't even use them all. So yeah, I think I do need more than 411.