I can’t say about XP or 7 but they’ve definitely saved my bacon on Win10 before on my home system. And the company I work for has them automatically created and it made dealing with the problem much easier as there was a restore point right before the crowdstrike update. No messing around with the file system drivers needed.
I’d really recommend at least creating one at a state when your computer is working ok, it doesn’t hurt anything even if it doesn’t work for you for whatever reason. It’s just important to understand that it’s not a cure all, it’s only designed to help with certain issues (primarily botched updates and file system trouble).
I did this during an international trip last year coming back into the country. The guy mostly seemed confused and kind of suspicious, but it was nbd.
They will potentially take you out of line to a side room to hand you off to someone else. It seemed to be an area where they deal with any oddball kind of things. There was a lady ahead of me who was more raucus and upset about some issue with her ID. The guy who checked mine mainly seemed kind of bemused, like it was unusual.
Be prepared for “We have the biometric data from your photo already, why do you care?”
You’re not obligated to give them a super detailed justification. Just remain polite and unconfrontational, and explain that you prefer not use the system as long as the right remains afforded to you to opt out.
(Note, this right only extends to US citizens)