I'm not familiar with the Behringer unit (never had good luck with Behringer products) so my answer was based on the Tascam line. To my knowledge, all the Tascam units that are control surfaces also are audio/MIDI interfaces. If you have just a control surface though, you would indeed need the other device for audio & MIDI connections. The control surface, probably using USB, is still both input and output, or at least it should be. You want to see faders moving on the device and the screen, whichever you adjust.

By the way, BIAB does come with built-in support for one control surface of sorts, the Frontier Design Transport. Although it's discontinued, I can vouch for it working great with BIAB.

The future is probably in iPad software. We already have a very nice BIAB Remote app that shows a lot of promise. I have most recently been experimenting with Splashtop Streamer to control the whole PC remotely.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.