Kind of. There's an "unlocker" that just spoofs their OTA endpoint to flash custom firmware because xteink decided to not implement TLS validation, though they could theoretically change that at any point.

Xteink also claims that non-domestic versions of their devices sold by their "official" store are unlocked, but there's been a bunch of reports that that's not always the case (...along with devices arriving with broken screens, not arriving at all, or the wrong device showing up).