I have on more than one occasion outed myself on CathInfo as a sede: sedeprivationist in regards to Montini, Luciani, Wojtyła, and Ratzinger; sedevacantist in regards to Bergoglio.
I have attended a SSPX chapel for 40 years and am a former STAS seminarian. I am SSPX Third Order. The last 2 priests to staff the local SSPX chapel knew me to be sede. I told them so directly when first meeting each priest, who are both Le Roux-formed guys unlike us older fellows who were formed by +Williamson.
I write all this as background to give context and form to what I have observed the past few years, namely that I have come to recognise and identity four varieties of persons to be found at an SSPX Mass centre in 2023:
1) Olde-Timey Palaeo-Trads (my group): People who have been around for decades. Many knew the Church before it was hit by the V2 rocket. Most came to the SSPX as refugees from the Novus Ordo in the 1970s/80s. They know Tradition and what the stakes are in this war.
2) Neo-SSPXers: People who came to the SSPX during the period when Fellay was Superior General. They tend not to care about anything other than Menzingen Inc. talking points and have a limited grasp of the history of Traddieland.
3) Legacy Trads: People, usually Zoomers and Millennials, who have grown up in the SSPX since birth. Because if their age, they have only known Fellay's neo-SSPX. They shared many attitudes with the Neo-SSPXers above and share much in common with them, but have never had direct exposure to the Novus Ordo apart from weddings and funerals.
4) COVID Refugees: Persons who began attending the SSPX during the COVID lockdowns because they had been deprived of Mass and sacraments in their Novus Ordo or Indult parishes. They are conservative Conciliarists with a predilection for classical liturgy. Their interest in Tradition is superficial and tends to fall in with the neo-SSPX since that is the only viewpoint to which they have been exposed in Traddieland.
I am intetested to hear critiques, nuances, additions, anecdotes related to these observations!