Automux
4
[Function]+Track on the OT will mute the track when in any mode. Works on MIDI tracks too. Also there is the part mute function that sets the first 8 trigs as mute buttons for each track and the remaining 8 for MIDI track mutes.
What you are saying about the pattern chains sounds like the arranger mode (song mode on the other boxes) but I never use it so I am of no help on specifics.