So these values can be found in the "TN_State.txt" file found in \X-Plane 11\Output\SR22 folder. They do have a note on not editing the file so edit at your own risk.
The values you are looking for are:
maint/flight
maint/hobbs
maint/nextTime100
maint/nextTime50
These values are in seconds so you'll need to convert your hours to the appropriate format.