As with any analog monosynth, there is definitely potential for mods, but I don't think the MS-101 has found its way into the hands of enough crazy people yet.

Tracing the circuits on boards with tiny components (to determine where to apply mods) can be more time-consuming than vintage through-hole circuit boards, but actually doing the mods isn't too difficult if you have the skill / experience. But it's definitely easier to ruin your synth if you don't know what you're doing.