Winner, Winner! CHICKEN DINNER!

Ok, so that DID work, albeit with one tweak: I had to place each of the 4 Digitone Midi tracks (I used the Digitone because 4 tracks is easier to experiment with than 8) on “All Channels”, after that, if you solo the midi channel of the track you want to play/hear (Trk 1, 2, 3, 4) and hit Solo, it works! Take a look at the photo below - I took this just now and it is working:

Note that the Digitone is set to Overbridge, and Autochannel is set to 10 (NOT 1, despite what Ableton support said regarding the Push2 being restricted to channel 1).