This video shows the prototype patch for cumulating relative controller input and the problem of M4L swallowing consecutive CC messages of the same value. I have set ThinningAggressiveness=0.0 in Options.txt before, but it did fix the problem.
The patch is a simple extension of "M4L.md.01.MidiInOut" just to find out,how to process relative midi messages. If I find a workaround for the lost midi messages or Ableton/Cycling74 somehow fix midiin/ctlin, I'm going to work on a high resolution dynamic CC patch with device parameter selection and acceleration adjustment, for smooth and precise filter sweeps. Hopefully the time resolution is high enough.
(Please excuse my bumpy English. I`m out of training)