I think that was the official tool from the toolset for Divinity: Original Sin 2.
I very much doubt it would work with BG3 effects, but who knows, i imagine even being able to load something, even if partially and with errors, could be useful to get some clues as to how the effect works and then make manual edits.
I guess you never know until you try. but i don't even know where to get the toolset now - a google search will probably yield something.