My talkback solution has been a wireless headworn (need my hands free to carry the iPad). Must have an input channel available and that can get tight depending on the band I am working with. I am already using up one channel to return an outboard reverb due to the DL's limited and inferior fx. Of course, due to the lack of programable input gain, I have to get levels sidestage before heading out front to finish the job.
When not moving around the room with the iPad, I place it on a music stand as opposed to a table with a big analog board and racks of outboard. Bands I work with joke that I look like a conductor rather than a soundman.