Thank you! I've spent the last two days looking for something like this.
I've decided to move from RPG Maker to Godot because while RPG Maker is great for non-programmers, as a programmer I keep getting frustrated with things not working the way I want. Unfortunately that also means losing access to the sprite generator in RPG Maker, which sucks because I am very much not a graphics artist. So this is perfect.
Played around a bit with the generator and I'm very happy with the results. Will probably do some combination of "prerendering" some parts while dynamically inserting other parts in-game. So many possibilities!
Looking forward to future expansion packs with more parts, I will definitely buy them!