Unlocking in the past

I have some 360 games that have discontinued achievements that I haven’t started yet.

I know that I can set the unlock stamps to be from when the achievements were obtainable, talking 10 years ago for some of them. But has anybody ever done this without repercussions from TA and/or Xbox?

Not sure how TA’s scanners work and whether it’d be auto flagged as the game wouldn’t have been scanned in before.

Don’t unlock online achievements if you care about True Achievements. They will 100% reset you and block you.

Ive done this quite a few times now and haven’t had anything happen from TA. It worries me everytime, but so far so good.