I'm pretty frustrated as I purchased an "unlocked" Z Flip 5G, which turned out to be an AT&T-branded device (not unlocked from Samsung as I hoped).

Because I'm not an AT&T subscriber, apparently I cannot download over-the-air updates and am stuck on Android 10.

I considered flashing the device myself with Android 11, but am only seeing two software variants, one for Spint (Sprint?) and T-Mobile.

I'd like to ditch the AT&T firmware in favor of T-Mobile's firmware – but is that safe/possible?

Will loading T-Mobile firmware on my "AT&T" Z Flip 5G brick my device?

This is the update I was considering >> Samsung firmware for the Galaxy Z Flip 5G SM-F707U with product code TMB from USA (T-Mobile). This firmware has version number PDA F707USQS1BUA2 and CSC F707UOYN1BUA2. The operating system of this firmware is Android 11.