G'day. It'd be nice if the editor UI was a separate "popup" window, like inventory and stuff, rather than in the top/left flows. For better or worse GUI stuff in them ends up pushing around other bits, and for me at least, often with that "transparent window with a scrollbar at the right" thing. (Too many status monitors in "left", I guess. :)

Anyway, I'm not in any way an expert, so I have no idea how hard this is. If you need a reference / example / person to ask, raiguard uses these in their "rate calculator" mod, and others, and I'm pretty sure their "flib" support library has a bunch of tools to make this easier.

(I'm sure you don't need pointers like that, but hey, maybe this is as hard as it seems from my seat, or whatever. No offense intended by suggesting that.)