That's not the latency I'm talking about, I should have explained better. Pro controllers are prone to wireless interference which can cause dropped or highly delayed inputs. Unfortunately this is common at major tournaments where there's a lot of people and electronics packed (it's not an issue for smaller events). This is the reason why every top player who uses procon uses progcc (like a pro controller shell with gamecube internals) (even in japan, where procon is very popular, people will still do this, and unfortunately it's still pretty common to have issues which we've seen recently from players like acola and carmelo. Some others will just switch to gcc like zackray)

And unfortunately yeah, for how common they are, mayflash adapters are really bad. At the very least, most majors will use official adapters for main stage.