Valid priests who still hold the Catholic faith can be found in the lines of Lefebvre and Mendez.
Not so fast. If you're going to hold this uncatholic, rigorist position for +Thuc, then you'd also have to hold it for +ABL, who would be doubtful because Liénart who consecrated him was a freemason heretic.
If you hold that +Thuc,
who was Traditional, had a mental lapse and his intention was invalid, then...
you have to hold that Liénart,
who was a heretic mason, had an anti-catholic intention which was surely invalid.
You have to be consistent.