A small addition to the topic.
https://github.com/armbian/build/commit/bd0b0354b5013e9f7629520bc7f841303247255a
Perhaps we just got a new best cheap adaptor, Comfast 915AC which runs very nice with this driver. I have 1W AP at 2.4G and within two walls and a lot of stations around making noise ... At the testing spot, my phone transfer rate is 20-40down/10-30up (depend on which time of a day I do the test) ... while running AP with this adaptor I get at 5Ghz AC mode more or less constant transfer rate 70/70Mbps. Note that it is 1T/1T only.
There is a variant of 8811au with BT radio, which it would be nice to test and a big 4T4R.