I have to disagree with you there, we own nearly 50 of the UNOs and use them constantly on shows that involve standard midi (note on/off, program change) MSC and MTC and have never had a problem that didn't eventually transpire to be caused by something else. In fact we have run MSC command over 100m of XLR using nothing but passive jumpers in the past, and even with that weak a signal they have been solid.
Exactly what problems have you experienced, are you sure there wasn't something else at blame?