Howard Miller

The advantage of putting the locks in the db is that it's much easier to see what the locks are doing and/or manually clear them if something goes wrong and you need to.

There's no formula for any of this. Read some of the discussions in the Hardware and Performance forum. Some of the Moodle Partners specialise in large Moodle sites but knowing how to do it comes from years of experience. I know myself from being involved in a very large site - it's the experience of all the things that have gone wrong

Might help to say which proctoring plugin you are using.

I have to say, most proctoring software I have seen makes me deeply uncomfortable. I think I'd prefer to find almost any other way thn (effectively) spying on students.

Usual first initial checks - are you using a theme that isn't Boost? If so, switch to Boost.

Do you have any plugins that might be injecting javascript onto every page? Turn them off.

Good question (to which I don't have an answer).

The bigger question is probably when various optional plugins support it (as opposed to core).