Based on the post of user bpwl and under my own expirience there is absolutely no change of the values in the VHT capabilities and/or HT capabilities part of the beacons. Whatever I set into the AMSDU limit or threshold (0,3839,1024,8192,..)- everytime I see only Max A-MSDU length: 3839 and Max A-MPDU length exponent 65535 bytes (3895 and 262143 for VHT).
I've tried it with and without capsman managing the interface. So far I'm using 3839 anyway and set priorities according dscp bits. I'm not going after some fancy super high speeds (as I have some old RBs with 100M upload ports), but I'd like to give my users the best performance I can afford.
My setup:
x86 CAPsMAN ROS 7.9.1
RB951/wAP ac/CAP ac/.. etc. CAPs ROS 7.9.1
Scanner method: Atheros 9285 b/g/n int. wifi + Realtek 8811CU ac USB with LizardSystem Wifi-scanner 21.03