Yes, I'd be happy to make the changes. What does that look like logistically? Sending patches to this mailing list asking for review? (Sorry, I know this must be explained somewhere but I haven't done much research about how to contribute to Emacs yet.)
I don't have a copyright assignment yet, but some kind folks are educating me about how to procure it over at the icomplete-vertical repo.
As an aside, have you tried non-fido icomplete? There is one simple change that makes it infinitely better in my opinion: fido forces a completion-style choice on you, icomplete gives you freedom to choose for yourself! (I shouldn't say so because I'm the author but I love the orderless completion-style:
https://github.com/oantolin/orderless.)