On Saturday I did a quick recording test with my son to see how this will provisionally work. It was good fun; he got to sing a bit of karaoke and I got to test out the mini rig instead of wheeling out my big 16 channel desk.
Zoom U24 interface attached to a Pi4 w/8Gb RAM running Reaper via 2 USB cables, (one for data one for additional power), provided Phantom power to my Rode NT1-a exceptionally well, so only the single power supply to the Pi needed.
Using my laptop here with VNC Viewer to control the Pi, but it's just as usable with a tablet or even phone. Sound files passed between devices using OneDrive.
Really happy with the outcome, and looking forward to integrating the Pisound pedal for effects!
Once both pedals are in use I'll then look to adding a suitable power supply for the two USB C devices on the board.