so aside from difficulty calibrating, can you get any response from the bike and the suspension talking?
if they seem to do something as you toggle options in the cluster, then is it voltage ? BMW dealer tools lock out any programming (which calibration is doing) unless voltage is above 14.5v to avoid programming issues. Many people don't have an adequate power supply to achieve this. I can imagine a GS 911 may have a lower voltage threshold to allow home bodging, but it could well be low battery volts stopping you.
You could try support with a battery charger