I do not. I've turned them on for some brief iperf3 testing in all combinations with and without SQM, but my conclusion was they did nothing: no impact on throughput, and no impact on CPU utilization. So I left them off.
https://forum.openwrt.org/t/throughput-drop-after-upgrading-to-21-02-mt7621/114888/7?u=eginnc