Six more months on CI, and even you will be a sede.
I think a sensible person who is not sede isn't saying that sede could never happen, they're just saying that there isn't enough proof yet of the position. For me, I err on the side of assuming Francis is a pope until proven otherwise. I realize neither option is perfect. The R&R have an obedience problem and the sedes have a universal acceptance problem. Both sides accuse the other and both sides are basically correct. Because I can't resolve it, I've leave it to God.
If someday the church declares that the see was vacant during this time I submit. If the traditional clergy ever unite in the conclusion that Francis is not a real pope, I would submit. If that happens in 6 months? So be it
That said even if that happens it does not necessarily follow that I would accept all of the conclusions of sede as it is usually in historically known. For instance Frances might not be a true pope. But that does not necessarily mean that the other post conciliar Popes were not true Popes, nor does it mean that the new priests and bishops all lack valid orders