Perhaps a more interesting and agreeable idea is to allow each user to specify their own .perltidyrc and put it in their user config. Then, the server could render everyone's <code> tags how each user likes to see them.

Obviously, though, this still falls victim the habit that many monks have (myself included), of putting various code-like snippets in <code> blocks (like command-lines, shell scripts, psuedocode, code for other languages than perl). That could be dealt with with attributes: <code lang=perl>, or with a new tag like <perl> which behaves the same as <code> except for the auto-perltidy'ing.

Anyway, I suppose it's somewhat academic, because it probably ain't gonna happen, regardless, and I don't know that that's a bad thing.