GT:CE is a very demanding mod, and I had an idea to create a pack that only uses its material system, but without the machines and recipes that slow the game down. I see some of its similar material parts have been added here, but not all.

Perhaps being able to add my own materials, given a texture from the resources folder, a name, and localization, this could probably be easier to implement, then just answering other people's requests about more parts. As GT:CE adds a LOT of sub part types, I think it would just simply be easier to implement above.

But otherwise, I fine with waiting for my request patiently like other people...

Most of the textures are stored here on their repo: https://github.com/GregTechCE/GregTech/tree/master/src/main/resources/assets/gregtech/textures/items/material_sets

As far as I know, most GT parts have been added, and anything else can easily be added as custom parts through the api. and no. The current api is name, color, and then you can edit models later.