MediaTek MT7981BA device
Since OpenWRT handles your WiFi too and it’s a MT79 device you have fq_codel built into the WiFi which might already be working with the default values for AQL. More info here How OpenWrt Vanquishes Bufferbloat
To get your desired results you can further tweak the AQL values as mentioned here GL.iNet GL-MT6000 - AQL and WiFi Latency
Other than that dropping speeds you put into sqm even further by 20-25% might help WiFi bufferbloat too.