I had an idea about this a while ago, but I have no idea how to implement it.
If a plugin could be put on an empty atom that has the same function as the clothing creator, assets and environments could be created from daz scene subsets rather than going through unity. That way you could have access to the materials from within vam and could do anything that you can with clothes materials. It's also possible to add mesh colliders, because stopper has done it with clothing items via plugin.
Just a thought. I'm just pixels and verts, I know nothing of scripting.
That's not an ultra big challenge, I did it for the Space Force enviro in a quite more "direct" way, that allows you to tweak the color of anything that uses the shader in my package.
You could obviously read the materials, grab the properties and generate a specific UI for every property. I do see a problem tho: creating assets through Unity allows a proper "build" of the assets, especially textures. You can bring a package with 50 assets and have something below 150 mb.
Doing that inside VAM means uncompressed PNGs, which is gonna bring the scene to stupid sizes, especially if you're doing every channel ( Diffuse, Roughness, Metal, Emissive ).
No matter how you try to look at this, at some point when you produce game assets, you need to use a proper workflow. And the effort you have to put into a plugin like this for what? 3 ? 4 or maybe 10 people building/editing a complete assets from the ground up?
Your idea is very interesting and doable. It would be pretty powerful for VAM. But not very optimized, and the amount of people using it would be extremely low. It's sad, I know but well... I'm pragmatic : 'D