Just thought I'd add a somewhat related data point to this conversation in case it helps anyone.. I bought my '22 GWS2O used, and warranty records show thermostat replacement around 10k miles.
At around 20k miles, I got a high coolant temperature warning, and pulled the car over and let it cool off. It was relatively low on coolant, about a 1.5" below min fill line. I found a dealer and purchased the appropriate coolant and filled to max-fill line. After this the car was drivable, but only for about 6-7 miles at a time as coolant temps would approach 240-250F. Temperatures would decrease by a few degrees at standstill (stop lights, etc..)
After the dealer looked at it they found a small leak in a hose leading to the thermostat (part # 68448246AB). They did note coolant was low, so it was definitely going somewhere. The part was on a slight back-order, will take a few days to arrive, but hopefully should be resolve after that. Car is still with the dealer (been about 5 days now), but will update once it's resolved.
Side note, they did diagnose a failed auxiliary battery and replaced it under warranty. I had noticed inconsistent auto start stop activation. Sometimes it just never activated despite me never manually turning the feature off, which was fine by me, but at other times it would auto start/stop, so I'm guessing this is related.