Another good option for this use case is the TC Helicon Blender.
Slightly weird design but it gives you a 12in 2out audio interface, or a standalone 6 stereo in 4 stereo/headphone out mixer. Takes batteries or wall power (not sure about bus power).
As a mixer, as long as you don’t mind the controls you use headphone 1 as the main output, and the others as post-fader sends.
It’s also all on mini-jacks, and the design is for several people to sit around it jamming, but it’s a bit cable spaghetti on your own.