Because each track requires a whole channel strip.
I'm confused about this. Are you saying that each track requires it's own output channel? They can't share? If my interface only has 4 channels, I can only use 4 tracks?
In the app, there's main output and 3 auxiliaries, all stereo, so that's 8 channels. Could there be 8 mono tracks?
Also, since I've watched Scott Uhl's videos, I've been trying to figure out how I will use the app. I'm super impressed with both the app and your helpfulness here in the forum.