No when I wore em off all four were worn off, well I assume, lost two and the other two were literally paper thin, so I didnt have an issue with that. If they stay on till they wear off probably not a farrier issue.
I am thinking in the endurance world my mileage is pretty typical.
The problems I am having now are on a different horse. She has only been shod twice since I have had her and I have just started putting miles on her. She is only front shod, The first time she was shod she lost one in the pasture the day before the farrier came, then this set I got about 3 weeks, 80 miles on em and lost one. I am fine with 4 weeks / 120-150 miles if that is what she needs, Its jusst that the shoe should still be there when my next apt rolls around.