It's just an odd situation. We have cinematic proof that one can leap into engaged range of a target and away from engaged range of a target. If the power allows you to leap to ANY location within short range or medium with the Range upgrade, then one should be able to jump to ANY location.
Example: I use leap to jump right behind a bunch of containment crates; I am now engaged with them and I have some cover between myself and the adversaries.
If it's true that you have to separately engage/disengage, then it throws out the RAW that you can leap to ANY location within your range.
Example: I use leap to jump behind the crates, however, I cannot leap directly behind them even though the power says ANY location within range, so I am only near them about 1-2 meters away and they are providing no cover at all.
Edited by GroggyGolem