I experimented it a lot, AKAIK it’s totally safe as long as you use midi tracks channels corresponding to audio tracks channels.
Why?
If an audio track and a MIDI track share the same MIDI channel, the MIDI track will block the audio track from sending out data while the audio track will block the MIDI track from receiving data
I encourage everyone to try it, new project, set a midi track to control audio track 1 on channel 1, notes C5-C7. Set corresponding CCS.
If you set all audio tracks on the same channel > Control All.
Some caveats plocking midi notes, sometimes you have to stop the sequencer to avoid plocks generated by loopback when you hold a trig (midi mode or audio mode). Should be optional imho.
I don’t remember why / how I had bugs / freezes, but I tried to control a midi track’s parameters with another midi track sending Auto Channel, so it was controlling itself, I let you imagine the nightmare to setup!
I remember having bug trying to control external gear with midi Thru (sending back midi IN). I didn’t insisted to understand the reasons, find the limits.
In not 100% sure in Follow TM mode for control in midi mode (midi control not effective unless you go back to audio mode).
Didn’t they solved that?