Not sure if this has been requested or not (I couldn't find it from a search).
It would be nice to be able to link multiple channels together with a simple option where they only broadcast to one channel. For example:
All 3 channels are linked although people in channel 1 can't hear what people in channel 2 are saying yet in Master channel they can hear all and talk to all channels. Also channel 1 and 2 are public so anyone can enter these.