802.11n - Bandwidth usage favors AP to station, make fair?

RouterOS Wireless Networking
1

I can transfer data at the limit of the ethernet port, on a 50 meter 802.11n link. Testing transfers in either direction has ‘scp’ reporting speeds of ‘10MB/s’ between two linux systems.

If it however run transfers concurrently, the transfer rate heavily favors the direction from the AP to station:
AP → station: 6.2MB/s
station → AP: 1.2MB/s
Total also drops to 7.4 MB/s, I get 10 MB/s perfectly when transferring only station to AP or AP to station.

Simply switching modes around (making the ‘ap-bridge’ a ‘station’ and vice-versa) reverses the transfer speeds when full duplex.

Q1: Is this normal?

Q2: Would this be solved by adding two additional R52Hn cards and another set of parabolic dishes to run nstream-dual in 802.11n (chained) configuration?

Q3: Could this at least be made fair with traffic queues and still retain the full single way transfers?

300 Mbps Full Duplex 100m link - Quest - Solved
2

If you consider how the protocols operate, there will probably always be a slight favor for the AP in terms of bandwidth.
However, signal quality can make it look like the opposite is true.