Frankly, I don't see what the "(Ultimate) Wiktionary redirect problem" is all about. You want to keep old links working, but not use #REDIRECTs for bad spelling?
Why not introduce #MISPEELING ? (or a variant ;-)
That would function like a redirect, with the exception that the destination page will, additonally, say on the very first line "You looked for the word or phrase WRONSPELLING. We believe you might mean GOODSPELLING (this page), of which WRONGSPELLING is a misspelled form."
Am I missing some intricate problem here?
Magnus