FYI, I wouldn't worry about server load of DPL unless it gets used many times on a page. Having it used 1 or 2 times shouldn't be too bad.
DPL can be tricky when used to pass data to other functions, so make sure it works in a sandbox. Many things function in theory, but there are unseen bugs and limitations that can bite you.
Cool... I see you based it off the version on Templates wiki. I should start using this template on wikis I admin.
FYI, copied the Verify template to the Templates wiki and it has some minor improvements as well as docs that don't have as many dependencies as the Fallout version.
So are you planning to copy the Verify template from Fallout wiki to this wiki? It's a good idea... The template doesn't look that complicated... You probably want to get rid of the "bug" part, tho.