ok
So this came up previously, possibly via Eventide user Brock (who knows stuff and some), and here is the MIDI version

H9 Hotswitch/Performance Switch via MIDI (acting inconsistent?)

How the performance/middle switch works in different algorithms:
TF: value 127 toggles between REPEAT on/off
MF: value 127 brakes the modulation, fast switching between 127 and 0 toggles FAST/SLOW modulation
PF: value 127 triggers FLEX on and value 0 triggers FLEX off
SPACE/H9 algorithms: value 127 triggers HOTSWITCH on and value 0 triggers HOTSWITCH off