Curious, it works fine and has full functionality as dedicated host, regards if you're running it in nw.js or a browser tab, so wondering what the problem is there. Is not like clients ever see what the host sees, depending on how you approach it.
Also, what is the benefit of running for own signalling server? Honest question, I really don't see it.
The main question I guess would be what exactly you want to see improved and how?
The solids issue you mention is hardly unique to multiplayer projects, and there are logical workarounds. Also it will likely be addressed in a C3 runtime update, which is planned for the future.