Simply put, I'd like to be able to load .obj meshes into the editor for replacing cubes with custom geometry for various use cases,
Something akin to what Figura can do with Blockbench Meshes in a sense but with the option to offset and scale the UVs for each piece.
As an example for how this would work:
You'd right-click on an added cube in the Player Model, the menu would include an option for "Import OBJ Mesh".
This would open a file browser to select a .obj mesh with, once selected it'll replace the shape of the cube with that of the mesh.
You can adjust the X and Y size and offset of the UV Map that the mesh piece samples from the skin texture, sort of like Per-Face UVs.
You can also change the Scale with Advanced Scaling Settings enabled, 1 Meter in the OBJ would be equivalent to a 1x1x1 Cube.
The mesh would theoretically be centered to it's pivot where the center of the .obj's scene is, though this can also be adjusted in-editor.
Shading can also have the option to be smoothed based on connecting vertices in the mesh, this can be toggled across the full model.
To revert a mesh back to a regular cube, right-clicking again will replace the option to import with the option to "Revert to Cube".
Safety settings can also have the option to control the amount of triangles a player model with meshes is allowed to render at a time.