I think there is confusion because he didn't always believe the Seat was empty since Ratzinger's resignation/Bergoglio's invalid election, as is the case with "Bennyvacantists". He has only recently come to this conclusion based on Bergoglio's heresy.
PS. Thank you Laramie.
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From what I could gather, he believes Benedict 16th remained pope until his death, and that there is currently no pope as Francis is invalid.
So yes, the word sedevacantist means "someone who believes the seat is vacant", but now Bennyvacantists are also sedevacantists, although the term "sedevacantist" usually means a "1958 sedevacantist". That's why I asked what he believes.
So he is Bennyvacantist.