Rollback is getting extinct for security reasons. When you will screw up, you need to do a new release. Hopefully screwed part is still talking.
First trip the repairman replaced all of the defroster parts and sensors. It failed again with the same code 18 hours later. The second time he replaced the main board and at least one other part. It now works great and I have effectively a new fridge aside from the compressor for less than $400.
Compressor still has three years of warranty left and we expect to move before then. It can (hopefully) be someone else's problem.
Main idea was locking updates to once or twice a year and resort to HomeAssistant.
It's at 33% execution stage so no idea on the feasibility.
Unusable devices are technically the most secure ones.