If it’s what I think it is, I documented how to workaround this elsewhere. There is a line in one of the CFG files which disables that slider, and that line can be changed.
If anyone does want to enable this feature for whatever reason, go into the “flight_model.cfg” file, and comment out this line:
;empty_cg_deviation_limit =0
It seems to work for me, for some values of work!
https://docs.flightsimulator.com/html/Content_Configuration/SimObjects/Aircraft_SimO/Flight_Model_Definition.htm?rhhlterm=empty_cg_deviation_limit&rhsearch=empty_cg_deviation_limit
