My issue is the part where canonical regularity is actually denounced rather than pursued given specific criteria. It seems like the Resistance doesn't even want to *dialogue* with Rome.
It goes back to canonical regularity meaning the compromising of the faith, which the resistance is resolved not to do, but is apparent that the SSPX is willing to do. It boils down to being canonically regular with error, which is what dialoguing leads to, vs remaining canonically irregular unless Rome converts.
You have to accept the fact that to the Modernists, tradition is a deadly poison that they only tolerate to a point, but ultimately, the only thing they really want to do with all things tradition, is to purge it out completely, that is Rome's end reason to dialogue at all. That's what Modernists do, Modernists absolutely hate tradition.
Rome dialogues with Islams, Hindus, Prots, Jews, queers and all manner of pagans, because they all have error in common, so they dialogue (sit around and get along), that's what dialoguing is. This is why the resistance denounces it.
OTOH, if Rome were to say "SSPX, please help us return the whole Church to the true faith," then the SSPX should and would actually have a very good reason to speak with them. As it is, all Rome says is "Let's talk this thing over, let's dialogue," and they say this in an effort to show the SSPX the error of their ways, so as to suck them into their newchurch.