Misalignment
No, it isn't how the flex plate is on the crank but how the transmission (doesn't) bolt up on a perfect centerline match with the engine, thus giving a slight twist to the flex plate which has to compensate (flex) on every revolution of the engine. Now I realize that it has the name flex plate but it doesn't actually flex in a rotational plane. I have not experienced any problem with this. Everything I know was from a post by Mysteryman.
Just guessing from a situation that did occur on a Scout/Case conversion we did a looooong time ago, if you don't have problems with the front (transmission) oil seal deterorating very quickly, it is probably just the extra torque and an inadequate original part.
But look back at the post from Mysteryman and (maybe) discuss it with your mechanic.
I will email on the possibility of being in your area.
James