My friend uses online gaming mostly, but he also uses gigabit 1000mbit. Trying to see if WED helps with him in this case? He had his SQM set at 750mbps or something, it works. But does enabling WED prevent this somehow? Since it's also a hardware aceleration method? He uses a Mediatek, AX59U, WED probably works on that.
In general you get 5-50ms added latency towards wifi client, it is not fit for fast paced games. You can try wifi surveys, get currently vacant channels, but as people acquire 5ghz gear the pleasant early adopter advantage will disappear.
WED adds more efficient offloading to and from wifi, you have to enable firewall offload to use it.
And see your other thread for sqm vs offload