Many linux users need the marketplace to be availible on linux. I would sugges a makefile (i.e users could be able to download it using " make MarketPlace" from github. Github build might not provide few minor features on linux which is fine ! But right now this is a major drawback and we only right now have this way:
Running windows VM (or another system running windows) downloading Unreal Engine download the asset from market place and make a package and import it in Unreal Engine on Linux.
Please Help or any other way or suggestion to use the market place on unreal github build.