It's still ongoing and I've just had the slowest one yet at around 50 seconds (didn't have telemetry on so this is very much an approximation). This slow-response page was Name Space which I'm mentioning here because it includes a lot of replies to the root node (280 direct, 395 total) and while I am totally ignorant of the PerlMonks internals this suggests to me that the problem might just be DB-related. So it's one more data point for those looking into this, anyway.