Aha yes I've seen this and it looks really awesome! I should install it and try it out, actually....

Something like this would, I think, make a good plugin (a plugin that could be shipped by default). Also, sorry for the suuuuuper slow reply - stuff's been kinda insane recently and I had to backburner Sapling for a while... I've had some new ideas recently so I'll hopefully come back to it soon.

This is cool, also it might be good to differentiate the IDs more in the first character (while still keeping these near the home row) to allow jumping to be quicker (having to press less keys to narrow down your "jump search"). It would also make sense to make the "words" or "nodes" that are farther from the cursor/selected node have shorter IDs, as generally if you need to jump you are trying to move a farther distance (if it is closer you can just do jj or kk or whatever). Finally, attempting to make jumps mnemonic based could be helpful (i.e. if you are trying to jump to a function it could be something like {CHANGE_MODE} f {FIRST_LETTER_OF_FUNCTION_NAME}{OTHER_EASY_TO_TYPE_CHARACTERS_IF_THERE_IS_AMBIGUITY}). I'll try to help with this if possible because this project is really exciting :)

EDIT: For the mnemonic thing having the currently used keyboard layout be configurable would allow this to also be ergonomic for dvorak or other keyboard layouts (making the suggestions be closer to their home row as well), but that is thinking into the far future :P