Can someone with a bit of knowledge on the subject clarify the testing procedures/timings?
Yeah, there isn’t any.
You’re required by law to assess risks and resolve issues where appropriate, that’s pretty much it.
For most regular office electrical items, looking at it is sufficient. Doesn’t have to be a certified PAT tester, just someone with half a clue. Going round sticking stickers on every cable known to man is an exercise in pointlessness.
Also, given that half the time they cover up actual useful information like the output details of a transformer, really bloody annoying. Well done, it’s safe now all right, it’s never going to get plugged in again cos I don’t know what it is. One year I’d to remove a bunch that they’d plastered all over the front of the servers, covering the intake vents and causing half the farm to overheat and shut down.