I’d be curious to hear more about the circumstances that ended up with a blocked runloop. Are there hundreds of junior engineers, or perhaps third parties writing code that you don’t control? I have seen people accidentally write blocking code, but not at such an egregious rate that we couldn’t catch it in code review, or at worst the runloop detector would alert on it in prod and we would roll back the deploy.
For instances where you actually know you need lots of CPU, there are now strategies for offloading that specific work, although they have taken a while to get nice and easy to use.