Be warned! Signaling that you understand signaling is a terrible signal, because it throws all your other signals into doubt.

This is the opposite of true. People want allies that are competent signalers. Explicitly talking about signalling is in most cases a bad idea and usually a signal that you don't understand signalling or respect it sufficiently.

Revealing that you are optimizing your signaling separately (for example, talking about "PUA") is among the worst signals of all.

To the extent that there are "worst signals of all" rather than signals being dependent on context and goals, talking about PUA wouldn't be near the top. There are more than enough cases where it is either neutral or positive---especially when that ridiculous acronym isn't used.