Just a minor suggestion that probably already exist but have decals where you can use them as opacity for bullet holes and such. Not just you know bullet indents in walls I mean if you shot someone through their shirt there would be bullet holes in the shirt, or cut through their clothes. You could do it with materials and such I am aware but a simpler more customizable method would be to have the option with decals. Also pretty sure an opacity esque decal mask could make for some serious sci-fi effects.
Side note might want to allow it to only affect certain materials as well so you know a hole in the clothes does not become a hole in the model behind it.