As far i remember, i spent more time on bringing NaviServer's https driver to its current state (A+ rating) than adding changes to OpenACS to support NaviServer. Current OpenACS works with AOLserver and NaviServer, essentially based on the result of [ns_info name]. Many of the newer changes are not needed to for functioning, but for improved performance.
The link [1] shows the changes in packages/acs-* in chronological order (starting 13 years ago) to give you a glimpse what's needed.