I suspect UDP should be fast enough to deal with a single controller stream, unless its getting bogged down with large amounts of additional data and/or coming in pretty quickly leading to dropped packets – > check UDP maxqsize settings? Another possibility is that it is there are network issues leading to irregular or dropped data – using wireless hub now?
If neither of the above is the actual source of the problem, maybe the controller data is at such a rate that it is placing a significant load on the max scheduler depending on what your patch is trying to do with it the causing it to become unresponsive. If that is the case, an appropriately placed [speedlim] may help.
I went through your suggestions but still saw this glitching in the associated jitter window, glitching I wasn’t previously seeing with a mouse as input. Eventually I put a slide after udpreceive and the glitching disappeared – not a solution, but it seems point back at the incoming data network, MRMR or iphone.