Nothing so far as I've just been a player of RM. But that said I'm working on a homebrewed fantasy world inspired by Poison Elves,Elflord,Fritz Leiber's Lahkmar & Thieve's World. Dark n' Gritty S&S style fantasy with Elves , Gnomes & other Fey creatures.
Plus I debating on creating a homebrewed Cyberpunk setting inspired by Steven Barnes' Aubrey Knight trilogy ,Bladerunner & GitS anime or Cyber-Post Apocalyptic setting inspired by Battle Angel Alita,Road Warriors/BTD ,Cyborg, Fallout & Doomsday.I'd be using the Cyberspace & SM2 rules for these.
Plus a conversion like Shadowrun to Cyberspace/RMC.If I can get access to the core SR supplements.