As a thought, while playing Elise and try to suspend myself in the air only to have my mouse over an enemy champion (Causing me to drop instantaneously), would it not be more feasible to rework Elise's E (Rappel only) to be a channel of sorts?
So that you simply need to keep the 'E' key pressed in until you wanted to drop or the timer expires, which ever occurs first?
This would allow for players to focus on using the Rappel ability without having the additional task of finding open ground to mouse-over just so that they don't instantly rappel back down into their possibly unintended demise.
I'd appreciate any thoughts. I'm not sure how to get the Riot Dev's to consider this as an option should it prove popular.