Schism is to take a rusty saw to the most holy Mystical Body of Christ. Cutting off a priest here, a bishop there, a group of Faithful here or there...
What a damnable deception of the devil!
Unless God told you otherwise, when someone professes to be Catholic (which means they subjectively adhere to everything the Faith teaches as they understand it) it's not our place to excommunicate them!
And if a priest is validly ordained and offers a Tridentine Mass, if you are a layman YOU ATTEND THAT MASS IF YOU CAN. It's not our place to issue decrees about what version of the Missal to use, tell the priest he must not utter Francis' name in the Canon, stay home because our feelings have been hurt, etc.
That is not our place, and God will not hold us accountable. Any more than God will hold me personally accountable for Roe vs. Wade being passed in 1973. Why would He?
However, if we stay home from Mass when we could have attended Mass, God will hold us accountable for that. Be sure of it.