Wouldn't that dramatically reduce travel available? You'd have to shift your upper mount further and run a longer shock to compensate and retain downtravel.
This is the major down side I see too, but it's manageable.
It will require the top of the shock to be mounted about 6" higher that it would if the lower tabs were roughly in the center of the axle. But I'm going to be running 14" shocks anyway, and probably have to cut the bed to mount them no matter what.
And I don't run a bed cover any way, so cutting the bed isn't a big deal, and it lets me do a stronger cross brace.