Honestly UV mapping for procedural content is going to be very dependent on what you’re doing. As an example, a terrain system I usually see people use some variant of triplanar projection texturing which doesn’t require UVs. For a block engine like minecraft it’s easy to hand create UV’s for each block, but will likely require something like texture atlasing or texture arrays. Now for a cave generation I’m probably going to say your best bet is more along the lines of triplanar, you can easily do multiple materials, and it will handle texture stretching.
The RuntimeMeshComponent won’t really help with UV mapping, it’s basically just a total replacement to the ProceduralMeshComponent.