Git Notes - Track rebase/etc + reverse-lookup for bugs ideas

Just wondering, has there been any looking into whether the git-notes concept can track rebases?

Reading over what git-notes is leads me to think it could be a good mechanism for the distributed bug-tracking idea I had some time ago. The only gotcha I see is that there would have to be some reverse mapping / fast lookup to track the commit objects that given notes are attached to.... and to facilitate individual assignment... notes applied to notes.

Example structure:

Commits A B C D Notes BUG Notes nA nC == bug notes

A <- nA
|\
B C <- nC
|/
D

nA <- BUG nB <- BUG

Operations for bug-tracking:

1) List all 'BUG'-type items that would refer to individual notes
2) List 'BUG' items reachable from a point
    Perhaps with criterion that a certain 'bug note' attribute is not  
set...
    or that a 'BUG_CLOSED' note is not attached to the given 'bug note'

... this seems to be somewhat of an extreme abuse of the notes system... but I could imagine it may have uses outside...