The large issue is breaking the 2 maneuvers per turn hard limit set by the system for balance. Nothing is stopping them from leaping -> engage or Disengage -> Leap however if you allow them to engage/disengage for free they can Leap->Leap or Leap-> Move which really messes with the games action and movement economy.
As i said it just doesn't really work per raw and per design without more convoluted/confusing/exploitable rules imposing limitations upon leap, either racial or force.
That said, a lot of us here are talking about the RAW and the design intent (as expressed from the order 66 interview) as that is the largest common grounds for rules comparison, debate, and discussion. The good news is RAW only matters if RAW matters. If you want to throw out RAW at the table well ... do it. Seriously chuck it out. The only important factor is that the group at the table playing the game is having fun. Different people have fun in different ways. Personally i like to stick close to RAW, however i do stray from it in places also. Everyone has fun differently and while i might have more fun with RAW, if i'm not a part of that group at that table ... well it doesn't really matter too much. I want that group to have fun.
However i would suggest to maintain the action/maneuver econ present in the game that if you allow leap to ignore engage/disengage allow regular movement to as well. It will maintain parity in the system and the balance envisioned by the design and RAW. But with that also, if ya don't like it, don't want it, or just think i smell funny chuck it.