To be honest, if a cloud vendor has technical problems with someone running a few benchmarks then that would make me very wary of said cloud vendor. What's the difference between a "benchmark" and "using all resources I paid for" anyway?
For established players it’s lost in the noise, but if it were me I’d appreciate a heads up for big changes.
And for what it's worth, I did actually work for a few small SaaS businesses, but a few reasonable benchmarks wouldn't have been a problem.
Of course, if your benchmarks are going to take 50 hours it's a different story.
Also: I suspect a lot of these database SaaS services are a lot smaller than you'd might think. I know at least one of them is anyway because I worked there (and there's no DeWitt Clause).
Give the vendor a heads up so the engineers can sleep.
And naturally, they were able to break it eventually, but they could have had all global employees trigger request 10 times per second and the system would've held and it recovered as soon as the load was gone. It was a silly deal, but now it's a great business partner.