Purgatory is a process more than it is a definitive place. Its a cleansing, a temporal suffering as God purges us of our wickedness to make us ready to be accepted into His eternal Kingdom. That said, I should certainly hope that purgatory is not just reserved to a certain sect of Catholicism! Its for all of humanity, athiests/protestants/everyone depending on how God judges them. Ultimately he’s the decision maker after all. Just trust that when we are all judged, we are going to be judged in fairness based on God’s will, and God hasn’t let me astray yet so when He says He is a merciful God, Praise be to Him because without that mercy, I don’t think I’d have a chance at purgatory even u_u