Excellent, so this looks like your APs are as good as can be expected right now.
At least in upload direction latency should be somewhat contained... but there is an on going discussion on whether the defaults for TXQS|AIRTIME_FAIRNESS|AQL are as good as possible, especially for users focusing on lower latency.
See:
for trying different AQL values and less convenient
for trying to actually get to change WiFi's fq_codel parameters....
But again, this will only help in the AP -> station direction and do nothing for the reverse traffic...