M4: Ableton monitor output included in loopback

[debacle]

Hi, likely I'm missing some simple thing and my terminology below is muddled because I'm a n00b, sorry.

Just got an M4, have my V-Drums mono output connected to input 3, headphones in the output jack, and PC connected via USB.

I want to (A) hear my V-Drums and my PC's audio in the headphones, and (B) record the V-Drums and PC audio at once in Ableton, as two separate tracks. I can do (A) or (B) but not both at once, which is what I want. (And beyond that I'd like to add more hardware inputs and send a different mix to each hardware output, but I get the sense that shouldn't add any new surprises.)

With V-Drums input monitoring turned OFF in Ableton, I can see the level indicators doing the right thing, i.e. when I hit the drums it only affects the input 3 levels and not the loopback. But then I only hear the PC output in my headphones, not the V-Drums.

When I turn the V-Drums input monitoring ON in Ableton, I can hear both the PC output and V-Drums in my headphones, but when I hit the drums it shows up in both input levels in Ableton, and recording the loopback input includes both rather than just the PC output separately.

I know there are separate "just loopback" vs "loopback w/ input mix" channels and I'm using the former.

Thanks!