My iksar can't get to the top of the ladder to attempt the jump whether luclin models are turned on or off. He just stops climbing once near the top so the spell vendors are unreachable.
Its all in the client. Nothing we have control over. You have to spin and jump near top of ladder. It is doable. Just not easy. H
Confirmed AKurate, as well. Even now, as an ex-Iksar, it would probably take me 3-4 attempts to stick that spin jump, hah.