I'm definitely not against this functionality, but I have my BigBox launchable from Kodi and can exit back into Kodi from BigBox using the app on this site. Same for Steam. Would this be a viable option for you also?
I guess it would be possible for any user to add a link from BigBox to any application really as its own platform. LaunchBox doesn't know whether it's an app, game, or emulator, it just launches whatever you tell it to.