I was curious whether there would be any issues running it on a localhost, but there weren't.

I have 29 plugins on at the moment. P3 itself took almost half the runtime.

It is [ahem] instructive to compare my 'dirt-bag' desktop localhost server performance numbers to the professional server resources that WPTavern runs on. I had been wondering if it might be worth buying a new if modest-end server-configured box ... looks like it's time to move on to piggy-bank assault & battery operations now.