Yes, the multi channel handling is a mess inside Ableton Live and M4L. Additionally the scene, mute and performance controller are all on different channels for the Rytm.
my device is currently far from “messy” but i’ve started with some changes which are currently in the final stage.
My solution:
At the beginning I had a device that stores 64 Presets of Mute/Solo, Scene and Performance combination, received by 2 dedicated devices to send the Midi CC To the Rytm.
Then I want, for live performance, to control a drum rack with the same device. So I’m added additional buttons to control 16 Drum chains (instead of 12 for Rytm). Mute will control the mute of the Drum Chain, Scene changes the scene of the Instrument Rack and performance changes the Parameter (up to 16 with Live 11). Everything without manual mapping only place the device in from of the drum rack. Out channels will be set automatically based on the name of the drum chain name (ending with 1,2,3,…)
But as you can see i have to add the additional 4 Performance controls.
It’s always necessary to work with receiver devices as workaround in Live.