As I have played FF11 for 6 years and FF14 now since Beta, I find that any form of jumping (even over small or short obstacles) would change the strategies of engaging enemies that the devs (enviromentalists) have built in, (other than what they now allow). I have often had to decide whether or not to engage a mob in a particular area because of the environmental limitaions. (Would I get caught by a low ledge or have to negotiate a fence or stone wall in order to engage or disengage & retreat from an enemy). IMO, If jumping is to be included, it needs to be specically related to accomplishing a quest or done only within an instance. Strategy and tactics are a part of what makes this game fun.