That thread, I think, overstates the issue. I have four BPI device (1 x R2, 2 x R64, 1 x R3), all of them with mt7915/7916 cards in them and I have had few issues and very favourable performance (in AC, and AX modes). In fact with WED, the performance and CPU issues are very good.
The two issues I have had have been DBDC, which a firmware change has cleared up, and with simultaneous AP + Client on a single radio on DTS channels, which is still an issue but easily worked around.
If you want to wait for WiFi 7, by all means, but I wouldn’t let that thread be what dissuades you.