We need uv-based-painting-layers. The keeping the stroke approach (Non-destructive) is nice for some.
But much more important than that for a characterArtist is being able to work on a model that needs changes in its geometry for example when texturing a head with closed mouth/eyes you often need to tweak the textures with a version of the head where the eyes/mouth are closed. It is utterly terrible for so long now not being able to do that with the workflow substancePainter is forcing on us. There is no technical reason i can see that would prohibit those layers. It is just the question of a mindset. This should be really remedied. It is really annyoing having to switch to mari for those cases.
I hope the devs find it in their hearts to free us from this pointless pain 😉