Doesn't this depend on whether the scope is balanced for a certain weight at a certain point? With my lightest eyepiece and the scope pointed near zenith, I have to dangle a counterweight from the UTA of my scope.
With a 31 nagler at the horizon, I have to add a 5lb counterweight to the mirror box.
There is NO weight that would be perfectly balanced near the zenith AND the horizon, so some form of counterweight will always be necessary unless the scope is so large the weight of the eyepiece is insignificant, or so "sticky" that the difference in the weight of eyepieces causes no noticeable balance changes.