Just open a ticket at support last week, we found out a bug in the kpa os.
In fact I was switching rig in a performance using CC, which takes almost 300ms. Support reproduce the same, which is an issue they adress to the dev.
Switching rig using Program Change is a workaround as we have 60ms then. So for everyone who experience latencw in rig change in performance mode using CC, use then Program Change. Just launch the switch 2 bar before (in 1/32) and it works like a charm.
Note that CC for stomps and wha are not affected from my testing.