BeatBuddy/Aeros MIDI Actions

Currently I use the MM to control the BB and Aeros (MM->BB->Aeros), so the chain is “unbroken.” I want to add another MIDI controller between the BB and the Aeros so that the other controller can control the Aeros functions like Start New 2x2 song or Mute Track 2, etc, but the MM still controls the BB.

So, my question is, if I send a “next part” message from the MM to the BB, does the BB send its own separate “next part” message itself to the Aeros, or is the Aeros message to switch parts just coming from the MM?

I’m trying to figure out if I need to keep the BB on “MIDI Merge” so its transitions and start/stop flow from the MM to the Aeros, or if I can switch the BB to “MIDI Out” so that only the BB’s messages (hence, start, stop, transition) get sent to the Aeros?

As a follow-up, it looks like this works with the BB on “MIDI OUT” (instead of Midi Merge), but the Aeros doesn’t seem to work unless it’s Midi IN channel is set to ALL. I tried setting the Midi IN channel on the Aeros to 2, and the BB Midi Out channel to 2, but that didn’t work…when I changed the Aeros back to ALL for Midi In, everything worked.

But the question remains…can the Aeros receive MIDI messages on individual channels, or does it need to receive on ALL (or Ch 1 only)?