This is the on thing that STV doesn't do and Tivo didn't do when I had it before STV. I loved using it on my dad's old projection TV years ago.
This is one wish that would be cool!
Picture In Picture with Swap!
I think this has been requested a few times in the past, but would need a lot of effort for little practical result. (I'd like it as well
I'm not sure if it can still be done, but previous versions could run multiple instances of the front end and you could have one smaller instance running on top of the main window. Well you could have as many as tuners available.