IDK, they don’t condone the use of these clients, and very few people (like me) come out to talk about using hacks at all. Everyone usually says “Of course, I don’t use hacks” and specifics into what hacks actually do are usually ignored.
In any case, I can’t be too sure as to why the client lagged so much less than Flash Projector. They’d have to dismantle the code itself and isolate possible causes as to why it lags so little.
EDIT: It’s not like experimental menu, I could still see enemy and player shots. I think less lag could be attributed only displaying the enemy’s health rather than how much damage is being done to the enemy.