Hm, I have to bring this up again:
While preparing my songs/rackspaces with external program changes I recognized that the assigned MIDI CC0 and CC32 are not always send when changing rackspaces according to the knob positions. However, the PC is always send?!
When switching between variations within the rackspace the CC0/CC32 are also only send if they differ (which is basically OK within the rackspace).
Meanwhile I made a full GPScript solution to always send MSB/LSB/PC after a dedicated rackspace/variation is selected/opend based on the knob settings.
But for curiosity: did anybody experience the same? What could have gone wrong here?