The 101 will usually accept a wide range of sync inputs, including samples of pulse waves, rimshots etc. If you’re thinking of replacing the MD with an OT, try triggering the 101 with a few samples from the MD. If it works with the MD it’ll work with the OT.

As noted, you’ll have to sacrifice a track for this, but that’s not a huge price to pay for syncing a 101 - and you can use plocks to program audio around the trigger samples if you need to (e.g by panning the aux output when the trigger plays).

You can also bring the 101 back into a THRU track for extra processing - I’ve been syncing a 202 via the A4 and processing it in an OT track, plocking overdrive and reverb etc. - great fun.

You could also expand later to add something like a Doepfer MSY2 (or a cheap auxiliary sampler) so the OT can drive the 101 via MIDI, freeing up that track. But having six or seven OT tracks plus a synced 101 is still a really strong setup offering years of excitement.