Well, even with my basically no instrumentation I can tell that I did something correctly when I told those user agents to fuck off, because top says I'm still only using about 50% CPU even though the migration of all my wikis involved turning on a bunch that were off.

Also I'm done migrating now! Woohoo!

(There are almost certainly damaged things in these wikis now that I am going to have to tinker with because of what I did with extensions. To solve that problem I'm probably going to do some shennanigans, but that's a later problem. Nothing that affects the reader experience should be broken)