It is entirely possible that it does use the headlight leveling sensor? I do not know for sure?

Once you have the 'Inactive' message come on, you may have to clear it using a code reader/scanner AFTER you have carried out any work. My icarsoft will clear suspension errors as will 'inpa'

When you refer to a "normal cycle" I am unsure what that is in terms of time? YOU really need something like 'inpa' to be able to see what the system is doing. That will show you if it is running to long/hot, slow etc.

The most common problem is the compressor piston ring fails (wears out) due to the system over running in an attempt to compensate for a loss of pressure (leak). People then fix the leak, but do not re-build the piston, which is now doomed to failure.

It is a neoprene/plastic ring so does not take too much to wear it out.

What I can tell you is this. On my 4.8, I thought the system was working as designed, until I rebuilt the compressor. Boy did that make a difference. The car raises & lowers in a couple of seconds. Prior to the rebuild that was around a minute.

I also note that with it rebuilt, it hardly runs when the car is being driven. Prior to that it would run for a few seconds at almost every stop light etc.

Good luck.