How OpenWrt Vanquishes Bufferbloat

Hi slh, I can chip in more "iw list" info about another beast ToH:Xiaomi Mi AIoT Router AX3600 -

root@OpenWrt_DumbAP_AX3600:~# iw list
Wiphy phy2
        wiphy index: 2
        max # scan SSIDs: 16
        max scan IEs length: 152 bytes
        max # sched scan SSIDs: 0
        max # match sets: 0
        Retry short limit: 7
        Retry long limit: 4
        Coverage class: 0 (up to 0m)
        Device supports AP-side u-APSD.
        Available Antennas: TX 0x3 RX 0x3
        Configured Antennas: TX 0x3 RX 0x3
        Supported interface modes:
                 * managed
                 * AP
                 * monitor
                 * mesh point

       ......truncated..............
     
      Supported extended features:
                * [ RRM ]: RRM
                * [ SET_SCAN_DWELL ]: scan dwell setting
                * [ FILS_STA ]: STA FILS (Fast Initial Link Setup)
                * [ CQM_RSSI_LIST ]: multiple CQM_RSSI_THOLD records
                * [ CONTROL_PORT_OVER_NL80211 ]: control port over nl80211
                * [ ACK_SIGNAL_SUPPORT ]: ack signal level support
                * [ TXQS ]: FQ-CoDel-enabled intermediate TXQs
                * [ ENABLE_FTM_RESPONDER ]: enable FTM (Fine Time Measurement) responder
                * [ STA_TX_PWR ]: TX power control per station
                * [ CONTROL_PORT_NO_PREAUTH ]: disable pre-auth over nl80211 control port support
                * [ SCAN_FREQ_KHZ ]: scan on kHz frequency support
                * [ CONTROL_PORT_OVER_NL80211_TX_STATUS ]: tx status for nl80211 control port support
                * [ BSS_COLOR ]: BSS coloring support
Wiphy phy1
        wiphy index: 1
        max # scan SSIDs: 16
        max scan IEs length: 142 bytes
        max # sched scan SSIDs: 0
        max # match sets: 0
        Retry short limit: 7
        Retry long limit: 4
        Coverage class: 0 (up to 0m)
        Device supports AP-side u-APSD.
        Available Antennas: TX 0xf0 RX 0xf0
        Configured Antennas: TX 0xf0 RX 0xf0
        Supported interface modes:
                 * managed
                 * AP
                 * monitor
                 * mesh point
   
        ......truncated.............. 

        Supported extended features:
                * [ RRM ]: RRM
                * [ SET_SCAN_DWELL ]: scan dwell setting
                * [ FILS_STA ]: STA FILS (Fast Initial Link Setup)
                * [ CQM_RSSI_LIST ]: multiple CQM_RSSI_THOLD records
                * [ CONTROL_PORT_OVER_NL80211 ]: control port over nl80211
                * [ ACK_SIGNAL_SUPPORT ]: ack signal level support
                * [ TXQS ]: FQ-CoDel-enabled intermediate TXQs
                * [ ENABLE_FTM_RESPONDER ]: enable FTM (Fine Time Measurement) responder
                * [ STA_TX_PWR ]: TX power control per station
                * [ CONTROL_PORT_NO_PREAUTH ]: disable pre-auth over nl80211 control port support
                * [ SCAN_FREQ_KHZ ]: scan on kHz frequency support
                * [ CONTROL_PORT_OVER_NL80211_TX_STATUS ]: tx status for nl80211 control port support
                * [ BSS_COLOR ]: BSS coloring support
Wiphy phy0
        wiphy index: 0
        max # scan SSIDs: 16
        max scan IEs length: 195 bytes
        max # sched scan SSIDs: 0
        max # match sets: 0
        Retry short limit: 7
        Retry long limit: 4
        Coverage class: 0 (up to 0m)
        Device supports AP-side u-APSD.
        Available Antennas: TX 0x1 RX 0x1
        Configured Antennas: TX 0x1 RX 0x1
        Supported interface modes:
                 * IBSS
                 * managed
                 * AP
                 * AP/VLAN
                 * monitor
                 * mesh point
                 * P2P-client
                 * P2P-GO
                 * P2P-device
      ......truncated..............
       
        Supported extended features:
                * [ VHT_IBSS ]: VHT-IBSS
                * [ RRM ]: RRM
                * [ SET_SCAN_DWELL ]: scan dwell setting
                * [ FILS_STA ]: STA FILS (Fast Initial Link Setup)
                * [ CQM_RSSI_LIST ]: multiple CQM_RSSI_THOLD records
                * [ CONTROL_PORT_OVER_NL80211 ]: control port over nl80211
                * [ TXQS ]: FQ-CoDel-enabled intermediate TXQs
                * [ AIRTIME_FAIRNESS ]: airtime fairness scheduling
                * [ AQL ]: Airtime Queue Limits (AQL)
                * [ CONTROL_PORT_NO_PREAUTH ]: disable pre-auth over nl80211 control port support
                * [ DEL_IBSS_STA ]: deletion of IBSS station support
                * [ SCAN_FREQ_KHZ ]: scan on kHz frequency support
                * [ CONTROL_PORT_OVER_NL80211_TX_STATUS ]: tx status for nl80211 control port support
root@OpenWrt_DumbAP_AX3600:~#

It seems that only the low end QCA9887 IoT phy0 (radio0) has full capabilities of:
* [ TXQS ]: FQ-CoDel-enabled intermediate TXQs
* [ AIRTIME_FAIRNESS ]: airtime fairness scheduling
* [ AQL ]: Airtime Queue Limits (AQL)

But both IPQ8074 phy1 (radio1) & phy2 (radio2) only has "[ TXQS ]: FQ-CoDel-enabled intermediate TXQs" capability....

Could it be due to the limitation of IPQ8074 or something more is missing there?

++ @nbd for the above query, thanks