USB devices seem to cause throughput regression as I've already described: https://github.com/openwrt/mt76/issues/70
it seems to have an impact particularly on TX path since I've managed to get RX 155 Mbps at 5m distance through a concrete wall
patching eeprom at offset 8036 to value 02 will turn on temperature control. according to eeprom guide it is needed to patch 8053 to 57, 8054 to 47, 8055 to BA, 80F2 to 0F, 80F3 to 09, 80F4 to 0D and 80F5 to 10 for full TC operation. in some cases the TX gain could be 1-2dB higher, but it depends on placement of router antennas and signal dispersion - it can get up to 4dB. at this point both TX & RX rates were still 300Mbps, if needed max power patch offsets 8064 8069 806E 8073 8078 807D 8082 8087 808C 8091 8096 809B 80F8 to 2E. that will allow to set txpower of 23dBm which gains extra ~2dB but affects TX rate