Kobo needs a hotkey for quick-flipping to the appropriate foot/end-note at the end of an ebook. Perhaps the "BACK" key could be mapped as such. I'm not aware of any real purpose for the "BACK" key while reading...I'm thinking...what does it currently do?
Even if a page, no matter how it's sized, has more than one note, the Kobo could flip to the first endnote appearing on that page and then allow you to page forward to whatever note your looking for, which shouldn't be too far away.
And if hyperlinks are indeed supported by ADE then most of the work is already done. The "BACK" button sets a temp-bookmark, selects the first hyperlink on the page...you read, flip through, whatever, and hitting "BACK" again returns you to, and deletes the temp-bookmark.
I'm sure it's not quite that easy, but I still have the hope, and expectation that the
Kobo is a work-in-progress. i.e. It's good, but could be better.