> Denying affiliation is a classic strategy in psyops. The alt-right and manosphere have established entire PR strategies based on that.
The same is true for attributing tainted characteristics to your ideological opponents - just call them "nazi" or "fascist" and anything goes. If they deny that they are nazis or fascists, well, that just proves they are nazis or fascists. This is called a Kafka trap. It is the same tactic used by so-called anti-fascists to legitimise physical assault on ideological opponents, they just simply call them "nazi" and start a "punch a nazi" campaign. It is also the tactic used by Ibram Henry Rogers (who took up the nom-de-guerre "Ibram X. Kendi") to be able to label people racist by stating that those who deny they are racist thereby confirm their racism. What all these tactics have in common is that they do not actually aim to confirm or refute the presence of a given trait, instead they are used to force another trait upon the accused - whether that be "anti-fascism" (which you referred to) or "anti-racism" (which Rogers refers to). Those forced traits tend to carry the name of the thing they supposedly refute while often encompassing elements of the refuted trait: so-called anti-fascists act like fascists, so-called anti-racists call for racism like the following quote from Rogers' "How to be an anti-racist": "The only remedy to racist discrimination is antiracist discrimination. The only remedy to past discrimination is present discrimination".
This can be generalised: the opposite of an extreme opinion is another extreme opinion, the opposite of an extremist is another extremist.
> I'd be more inclined to trust a person/collective declaring they anti-nazi (or antifascist if you will), than a person/collective declaring they're "not a nazi" then leaving traces of nazi symbolism everywhere.
Honest question: would you be more inclined to trust a person or collective declaring themselves to be, say, anti-communist than one declaring not to be communist? I have seen a glaring discrepancy between the trust put in so-called "anti-fascists" (who more often than not are all too happy to use the same tactics as the original brownshirts used to spread their ideology) and that put in those calling themselves "anti-communist" with the former being given the benefit of the doubt while the latter are watched with suspicion since they may be "right-wingers". Well, yes, they might lean to the right, just like those "anti-fascists" most likely lean to the left. Whether that makes the one better than the other depends solely on your ideological standpoint and as such is subjective, not objective.