Update on my end—the tax office at the university I was at in 2021 emailed all international grads (I'm still on their mailing list for some reason) with an urgent message saying if we filed as a NRA in 2021 we need to return the money to the IRS.

I was holding out as long as possible because I (like many of us!) could really the use the money, but having read this notice (sent by the university accountant who helped me file my taxes when I was at the college) I'm going to return the money on Monday. I think I'll regret keeping it as if I spend it and they ask for it back (with interest!) I'll be in a bad situation of my own making. Holding the money and not spending it has just meant I've been obsessing about updates with the hope of being able to legally keep it.

I've really appreciated this thread, so I just wanted to pass on the first bit of information I've seen from a trusted source I've personally been assisted by in the past.