There's also another annoying issue with the multichannel designs in Altium. The underlying assumption is that all channels are orientated in the same direction. You can't rotate some of the rooms because when you do a global copy of the room format it will reset the component and track positions back to the orientation you are copying from. I'm not sure how to get around it.
You can't directly.
What you can do is lay out one room, and select which room you want to apply the copy to.
You and then lay out another room and copy that rooms format to other rooms.
That's the work around for different shaped rooms.
If it's just a rotation issue you can apply the changes to all rooms, and then rotate those affected.
Annoying? IMHO it's way more useful than not having room copies being available. However, I'd bet a dollar that this is a feature that's dropped from the free version, and I could agree with that.