I'm pretty sure that they're only converted from the short cuts ([mod://]) on page render, so when the code changes, they'll all go to the right place.

Quite right but only where the shortcuts were used. Some users use, or have used, raw anchor tags or the full URL in brackets.

Indeed, but I don't know what the percentage is, my guess would be that it's reasonably small, perhaps so small that it's just better off relying on the redirect that will soon be in place at search.cpan. Worth noting and checking later I guess.

Update: fixed typo, thanks pryrt.

Long-standing site policy is to leave writeups with whatever broken links they have. Of course, if there are important ones, e.g. which have become de facto reference works, we may edit those to be unbroken. If you know of any candidates, please use the consideration process to bring them to the janitors' attention. (Or if you're a janitor, exercise your discretion directly. TIA!)

I reckon we are the only monastery ever to have a dungeon stuffed with 16,000 zombies.