Sorry I missed it on the GC forum otherwise I'd have replied.
The best place to ask this is on the Geocaching.com web site forum on GC. Jeremy (the owner of the site) frequents this forum and will see your request.
As the UK Greasemonky script Guru was able to produce one to replace the default maps on cache pages with OS ones, maybe he can produce another one for the map link for Additional Waypoints.
Personally I have the benchmarks.org bookmarklet that I use to look at the location of Additional Waypoints and have no problems with having to use it, and I see 20-30 caches every day.
Additional Waypoints were created to be a Reviewer tool, the bonus that came out of the development of them was to allow Premium Members to be able to down load them in a PQ and input then straight into their GPS's. Their primary purpose is to allow Reviewers to us them in Reviewer Tools to check for proximity issues to other caches or their components.
My post is my personal opinion and as such you do not have my permission to quote me outside of these forums!
Dave
Brenin Tegeingl
Formerly known as Mancunian Pyrocacher on GC