Maybe anecdotal, but I flew out of town last week and my IG was at the airport parked for 3 consecutive days. When I returned, I loaded up and went through my normal process, i.e. Auto Shut-off, A/C adjust, Favorite to deactivate Intelligent Speed Assist...( do the ADAS last because the infotainment process speed lags so much).
When I went to deactivate the intelligent speed assist, it was still off from Monday.
But on the way home I made a stop (<5 mins) and when I got back in it had reactivated.
Not challenging anyone's knowledge of the system. Just point out that, in my opinion, there is no rhyme or reason when it resets vs. when it maintains the setting. Certainly, more time than not it resets, but I will say emphatically, not always and I can't figure out when or why.