Lifter plunger in the 59 deg toilet

If the pushrod angle was causing the problem all the lifters would have failed.
You have other issues.
What does the outside lifter surface and the lifter bore of the failed lifters look like? Did you measure them?
I have small scuff on the cylinder side of the top and a small scuff on the bottom cam side. This I would expect due to lifter angle.
I have not measured.
I’ll check that tonight.