Thanks for the suggestion! That's exactly what I wanted to accomplish (whether I explained it clearly or not), but having HTML::Template itself handle both passes hadn't occurred to me.

I doubt that it would take more than one or two site-wide changes to more than make up for the extra work involved in setting it up. (Plus one extra site-wide change in my case, since I'll need to make a site-wide change in the process of doing so...) And how many sites go their entire lifetime with only one or two site-wide changes?