If you take the position that Pope Francis is an antipope, and that Benedict XVI is still the true Pope:
(1) What are you going to do if Benedict dies before Francis, thus, in your estimation, vacating the See of Peter? What if Francis lives on for years afterward, filling the College of Cardinals with his own nominees? When Francis then dies, and a conclave convenes, how will you accept the result, seeing that it was arrived at by “cardinals” appointed by a false Pope? Will not the line of Popes have been brought to an end?
(2) What are you going to do if Francis dies before Benedict, and the conclave elects a truly holy, reforming and Catholic man to be the successor of Peter? Are you not then in the perverse position of opposing that true Catholic as an antipope, and holding as invalid all his purportedly papal reforms, seeing that, in your estimation, he was elected by a conclave invalidly convened while the See of Peter was still occupied?
Haven’t you painted yourself into the corner of sedevacantism?