There is no lack of bottom bouncers on the Stave and the Vedder, and it seems worse to me in sockeye years. We havent had a sockeye opening in some time so we'll see in a couple months if that special technique increases on the other rivers this year... However I do think that sites like this do help as I also see more people using like stuff like spinners spoons and jigs in recent years.
FWIW I fished the stretch a few hundred meters below KWB a couple times last season and didnt see a single flosser. Everyone was 100% legit.
The OP has good intentions but chironomidking is right in that as long as flossing is legal, no one has the right to tell anyone else what is the 'proper' way to fish. There's no such thing, though we can try to educate and encourage other methods as much as possible, though if the FWR community say flossing the Fraser is A-OK but not the Vedder seems very hypocritical IMHO.
re: snagging enforcement, it's really hard because you have to literally catch them in the act of foul hooking and retaining said fish. You cant inspect a catch after the fact like you can for many other violations.