For me iti is only abbout the C172 with G1000 for now.
Following the same procedure as autopilot master On/Off ( toggle ) and Autopilot On and Autopilot Off ( Events to fire ), I would suggest trying with :
AP_LOC_HOLD_ON / AP_LOC_HOLD_OFF : Localizer
AP_APR_HOLD_ON / AP_APR_HOLD_OFF : Localizer + Glide slope
I have yet to program these two on my Panel but am confidennt they will do fine.
For feedbback , or request or reading (the same meaning ) I would use
AUTOPILOT GLIDESLOPE HOLD / AUTOPILOT APPROACH HOLD ( toggle ( bool ))
I dont really think there could be a specific command ( event ) for each type of Aircraft in the Simconnect specifications, not that I have encountered such in my readings .
Int his kind of things , the concept is for all the same , if youconsider that ILS is an international Standard…should be modelled as such too.
Give them a try
Greetings
Franncisco