Vertex group control for cloth simulation mass setting

This is a feature that used to be in Blender years ago I believe, and now I need it and it's no longer there!

In my scenario I'm trying to add mass to the hem of a skirt (relative to the rest of the garment) to give inertia where there is an attached heavy fringe of hair particles. I've been trying to hack it by adding extra geometry in that area, but it's introducing all sorts of issues with collisions and especially self-collisions, and generally messing with the already working cloth-sim in tricky ways that are taking me round and round in circles.

Now with fancy mockup! I'm hoping this could be retro-fitted...er what's the opposite of retro fitting? to Blender 2.90 cloth sim, which otherwise works so awesomely now. Even though the base of users pushing cloth-sim boundaries in production is probably slim, it would be a great (and maybe simple-ish to implement?) addition to the pro tool-set.

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Non-programmer thoughts on implementation:

I imagine the scaling factor could have a range to maybe 100, and would act as a multiplier to the base vertex mass and vertex group, for easier testing and iteration.

And I imagine the vertex weight could be additive with the global mass value. So:

• without Mass scaling, cloth vertex mass is global
• with Mass scaling enabled Vertex mass = (Base vertex mass + Vertex group) * Scaling factor

This would mean the cloth would still adjust to the Scaling factor, but not go to mass=0 with a vertex weight of 0. This seems a logical setup for keeping values in a usable range.

In other words, the global vertex mass would generally remain the minimum, and by default the vertex group could double the mass with a vertex weight of 1.0, and this range would scale up and down with the factor, but leaving the cloth always with some usable mass, even at low vertex weights.

Please chime in with other ideas though.

Potential uses could be:

• making wet areas of clothing
• adding mass to other decorated (say heavily embroidered) areas
• adding mass where rigid accessories are attached (since cloth+rigid body interaction isn't there yet)
• simulating multilayered clothing while keeping geometry simpler (think heavy denim pockets)
• tweaking masses of areas of cloth-simulated manifold meshes (like the one I'm using as a meshdeformer for the pearl necklace below)...

This is just the beginning! Thanks for reading and considering.