Maybe you already thought of this but I’ve learned to just treat all pieces of hardware as “accompaniment”, that is, don’t even try to sync multiple Elektron devices pattern-for-pattern to create “scenes” a la Ableton. Give each box a set purpose and control them all manually.

That said I had success sending program changes from the MD to an MPC1000 to add long phrases on top of beats, synced to tempo. MD makes a better master than slave as it turned out… maybe try reversing the hierarchy. OT might respond better.