Looks like any attempts of copying Valve’s features have a side effect of forcing you into Valve time while implementing them!
Jokes aside, it’s been a while since I checked this thread. In fact, initially when I did, I was barely starting to get accustomed with the engine. Two and a half years later, I’m feeling pretty confident with the C++ side of things, but unfortunately, materials aren’t exactly my thing and not something I’ve managed to master to a satisfying extent.
With this said: not to sound too insistent, but I think if you release whatever work you’ve managed to accomplish so far, it is more than likely that someone will pick it up and finish. Otherwise, it will basically never get done. I understand the desire to make it perfect, but the speed of progress nullifies all noble intents. It’s been in a state of “almost done” for years now.
So, unless your intent is to sell the feature on the marketplace (which is understandable and completely fine; if anything, I’d be among the first buyers), then I really do suggest letting the community finish it. It’s an amazing thing and would benefit everyone.