Now I will preface by saying this is a fairly major request and I honestly don't expect it to get accepted, but I'd like to pitch it anyway:

Minecraft 1.20.2 introduced a complete restructure to GUI assets which, while a slight hassle to convert to, opened up new possibilities for pack creators and made things much more modular. My suggestion is also doing this for EMI.

To give it my best sales pitch: Allowing all (or at least most) textures to be individually mcmeta-ed per-resourcepack would give way more freedom to pack makers to adapt styles for EMI. Just being able to nineslice alone would fix all issues I've run into while trying to develop one, and that's without considering animations on top of that.

Another thing I noticed while working with the new asset structure of 1.20.2 is that it's quite a bit clearer what everything is. Static GUI atlases are bulky and heavily restricts small modifications, which also extends both ways.

Anyway, that's all the upselling I've got cooked up. Again, I fully expect this to be out of the realm of possibility for various reasons, but it sure would be great to see.

This is both something I'd like to implement and something that would cause notable burden. Currently, EMI supports all versions from 1.19.2 to modern day and probably will continue to do so for a while (there is even a version of EMI running on 1.4.7!), the problem with this version agnostic model is it's hard to justify using modern features, since that requires either backporting a facade of them to old versions, or duplicating everything depending on version. I'll leave this bug open because it's something I would like to implement but it is worth mentioning the issues.

Thanks for putting it in consideration! Definitely understand how it's not some straight forward thing haha