Ah, to hell with it, I upgraded to 2.10 now that it is officially available in my territory, and luckily no more light bug. I'll live with Amasis for the time being.
Anyway: I don't know how long this has been a feature, but I only saw it now: previews of footnotes! And fast, responsive ones at that. I tried with Infinite Jest, figuring if any book would bring my Kobo to its knees with the footnotes, it would be that one. But no, as snappy as you could want, it first displays a preview of the footnote, with options to go there or cancel. If you go there, it is near instantaneous, and the same going back to the text from the footnote.
If this has been there all along, I apologize
(Also, being able to look up words from inside the dictionary is super great.)