Using two different audio interfaces at the same time for recording AND playback in a single audio program like Studio One:
Windows: No!
Mac: Yes
However, in windows you can use different audio interfaces in different audio programs:
For example: AI-A in Studio One for recording and playback AND AI-B in Notion for the same purpose. Or you can use another AI (or your internal sound card) for youtube.
In Studio One you can change your audio interfaces for different recording sessions (or for another songs) at any time.
gottfried