If he submits, and plays along, it's a bad sign. A really bad sign. For this one action will speak far louder than any of his multifarious words. It will prove him for once and for all.



What are you talking about? Whether he's sedevacantist or not has nothing to do with the accusation from new-rome.
Even if he believes that new-rome is in a sedeprivationist state (i.e. still has natural, temporal authority...which is the most likely scenario), then submitting to their natural/legal authority is wise (and an obligation). But any spiritual/theological authority they "impose" is null and void because it will be based on V2/new-age/humanistic errors.
Thus, as St Thomas Moore did, he submitted to the (nefarious) authority of King Henry VIII, when the King called him (legitimately) to a court hearing. But St Thomas did not submit (and refuted) the King's authority to compel him to accept the heresy of Anglicanism.
The difference between authority/summon (presence) and the authority/accept (heresy/facts), is quite distinct in the law. Your error is you fail to distinguish.