Working with octatrack and digitone and digitakt through the midi through on the digitone for that matter.
All patterns set to the same length for them to change at the same time. So A1 could be 16 - A2 might be 32 etc. - as long as they all match up in length or I actually think if the slave is set to less than the octatrack then it will also change on time. You just can’t have a longer pattern on the slave machine.
So you could have a pattern of 64 on the octatrack with patterns of 64 or less on the slave and it will still change on time.
Octatrack is set to channel 11 for program change send. The digitone and digitakt are set to auto channel 11 with program change set to auto channel
Set program change per pattern inside the octatrack. Double tap SRC to set the program change. (Same window you’d pick the midi channel for each track.)
So A1 would have a program change of 0
A2 would be set to 1
A3 would be set to 2
This is of course if you want them all to change with the same patterns. You could set the program change to any number for any pattern on the digitakt or digitone.