Sorry, I’m still not seeing anything that could be pulled into Unreal. It just looks like Marvelous Designer clothes being pulled around in-program.
The problem with that is that the clothes need to be animated using each unique, in-game character. Even using the Unreal stock figure wouldn’t help, as no-one would use that for their game. Are you planning to make clothes just for people who have Marvelous Designer? Because those are the only people this would help, as far as I can see. I don’t see how this would be a good fit for the Unreal Marketplace.
You also haven’t addressed LOD, either.
I’d be (very) happy to proved wrong, though, so please let us know.