Hi Tau, thanks for the report!
Though I have to work this afternoon, I'll look into it this week to see if there are bugs.
The edit-channels, to be short, can be controlled over midi. If you look at the code in the midi, you can see that you can select an "edit" channel (which row you want to edit: edit, mute,solo,scaled).
channel 0, CC57 toCC60 should select which row you want to edit (any value from any of these CC's will select a row).
with channel 1, CC1 to CC16, you can toggle off/on the channels in the row (also any value, it just listens whether the CC changes).
About the "active" input, this indeed just only sends an "all-note-off" message.
You should also use the control for this input to stop the counter module that's driving the polymidiXL.
I added this just for resetting the midi-on-notes when the counter would be made inactive.