|Perhaps your posing this question in the XP General Forum is a less-than-perfect choice.... did you think of that?|
Your Subject line is "
Unpacking UTF-8-encoded ZIP archives", yet it appears your real interest is in conversion tools. Further, you want the first "conversion" to happen during the extraction (like asking ***zip software to translate a language on-the-fly, eg.: English to Pashtun). And even further yet: "...convert recursively the whole structure into UTF-8 after the extraction...".
It becomes rather difficult to comprehend the apparent-convoluted objective.
A re-phrasing, or better fleshing-out of the question might be in order... but this is not the forum for it.