Well, wouldn't it be better to remap keys to numpad? Plenty of keys there and you can use "0" for jumping. ;)
I have done this (num 0 for jumping, + for running and num / for focus).
But it still feels awkward, because 'jumping key' is not just used for simple jumps but also do go down and through gutter doors. If you combine this with running you have to use all 5 fingers of the right hand for simple movement actions.
Ok, I'm a lefty and always played with num-pad instead of WASD and so will eventually get used to this, but it's just unnecessary complication.
There really should be an option to freely reassign all mouse buttons, especially in these days with all the multi-button gaming mouses out there.