I mean, it's easier to load-test Nostr than most other systems because you don't have to create user logins and you can write straight to the data store.

You can just use NAK to auto-generate nsecs and go for it. Could generate hundreds of them on your laptop and have them all running a Jenkins script, asynchronously. With a good graphic card, probably thousands of them.

Not even just writing to the relays, but fetching, clicking buttons, typing, etc. So, you can load-test the apps, as well, and take down websites.