Yes, it's running on master snapshot. It should be the same for 23.02. Sorry I forgot to mention this.
Why old ? Is it deprecated ? I can't find this info. I have simply setup wifis using Luci.
I own two and manage a third one: I'm using mostly 5GHz and can achieve 40 MB/s when transfering file from a desktop to a laptop. I'm poorly using 2.4GHz (and old device from time to time), but it works as expected (12 MB/s). So far I'm satisfied by the performances that are according to hardware. I have used 19.07, 22.03, 23.02 and a lot of various snapshots on all these three models.
I have also read several issues reports but I can't figure out why (bad config, bad models ?).
Recently there was an issue for snapshot (Probable wifi regression in mt7621 snapshot) but that was a simple bug correctly the day after. I can't call this a driver issue, just a setback.