Seems like rust hard limits the number of custom radio stations you can have from 3-4. I am aware there are plugins out there that are client side that can solve this but that obviously has security issues (ie leaking client ip info etc). I am also aware face punch devs put this limit in to prevent network bandwith issues etc, but should not be a problem for dedicated servers with good network bandwith. No ui needed, something simple just being able to add via rcon or server.cfg