It's thousands of requests per minute, I counted 5000 on my PC, probably different depending on hardware performance. And that's just for ONE tab. I usually have a lot of tabs open when I'm exploring dramas.
I would say this is a bug of very high importance, as it affects users computers, affects MDL servers, performance and stability.
I've noticed this for many days, my firefox browsers always at 100% cpu load and I've had to force end the task to gain control of my pc, since I always leave some MDL tabs open.