I think you're losing it even worse than usual. Is it due to your premature celebration of Brother Nathaniel becoming Resistance, where you spiked the football before you made it into the end zone?
SSPX existed long before the Resistance, and Bishop Williamson had been an integral part of it. So it's just a bit anachronistic ... and totally nuts ... to proclaim that SSPX exists to keep people from the Resistance.
People's need for the Sacraments far outweighs the principles of division between Resistance and SSPX and those priests are absolutely right. Resistance have far too few Mass centers available. Nor is someone apostate or Modernist simply for attending SSPX Masses. I have rarely heard a sermon about the crisis from an SSPX priest where there's even some risk of people being "corrupted" either.
According to you, I am "dogmatic sede", and yet I have no problem going to an SSPX chapel for Sacraments provided they don't send a Novus Ordo presider who hasn't been conditionally ordained.