The GoFast rocket is considered to be the first amateur rocket to reach space, beyond the Kármán line. The rocket was spin-stabilized through ascent. After reaching a certain altitude, it used the yo-yo de-spin mechanism to reduce the spin rate.
Flat-Earthers noticed the rocket’s spinning motion suddenly slowed, and they used it to “prove” the rocket “hit a barrier” up there. In reality, a yo-yo de-spin mechanism was deployed to slow the spin, but the rocket was still going up for some time afterward. — Hitting a barrier would have destroyed the rocket.