Well, the problem with that is a) modifying multiple implements and b) it's inherently inconvenient to build a rigid add on to most implements, given that most implements have only a single hoe at the top link.I'm thinking an adapter fabricated to be a semi-permanent addition to the implement, with a bushing at the front of the adapter that stays rigidly at a consistent height so the hook can find it.
I've gone full circle now. I'm back to thinking of starting with something like the Titan QH that already has plates with multiple pairs of holes, and just welding on two more plates above that increase the adjustability of the top hook more.
Yes, you have to move the Top Hook for each (or most of mine anyway), but you have to get off the tractor anyway to do the PTO; what's one more small step...especially if the hole pairs are colored for each implement. Nothing's ever as easy as it first looks.