I've been testing with a MBP M1 and a RT3200. Setting he_su_beamformee = 1 and he_bss_color = 8 seems to slightly improve performance, but I still see a sharp decrease by moving as little as one step away from the router.
From:
signal: -63 [-68, -70, -70, -67] dBm
signal avg: -63 [-67, -69, -71, -67] dBm
tx bitrate: 907.4 MBit/s 80MHz HE-MCS 9 HE-NSS 2 HE-GI 1 HE-DCM 0
rx bitrate: 816.7 MBit/s 80MHz HE-MCS 8 HE-NSS 2 HE-GI 1 HE-DCM 0
to:
signal: -65 [-67, -70, -71, -72] dBm
signal avg: -64 [-67, -70, -70, -71] dBm
tx bitrate: 907.4 MBit/s 80MHz HE-MCS 9 HE-NSS 2 HE-GI 1 HE-DCM 0
rx bitrate: 34.0 MBit/s 80MHz HE-MCS 0 HE-NSS 1 HE-GI 1 HE-DCM 0
Notice how the bitrate drops from 816 to 34 and HE-MCS drops from 8 to 0, with a RSSI drop of just 2dB.