Using the GBA version? Are you high? That's like deciding to make a Doom level editor that edits the SNES ROM.
Just what I was thinking. A link to the past is a SNES game. Every study of A link to the past was done for the SNES version (obviously). Original authors simply traversed this game onto the GBA, to also make it available there. But essentially the GBA version is a poor copy of the original, with much more complicated engine, less appealing for editing.
Did you know that A link to the past is also available on Wii. So why don't we edit the Wii version?
Maybe we should change the subname of the forum: Your primary SNES A link to the past hacking resource.
Of course we are also prepared to accept topics, that try to modify other Zelda games, and Alttp-GBA-version is such a game. Since the engine is completely changed, this is a different game (but because it looks the same and even has the same name, it can confuse lots of people). But don't be confused: the GBA version is a different game (that needs its subforum or subtopic).
I hope this is clear now. We edit something for SNES, and the GBA version is for a different console. Or in other words: completely incompatible.
It even goes further: the SNES EU version of Alttp is coded in a different way, than the SNES US version.
So that's what we are editing: the SNES US version. Everything else is not compatible.
So: if we are talking about Alttp modding, and you bring up the GBA version, you are unfortunately completely off course (unless you want to study a completely different game).