I think my biggest question might be addressed in the Midori article: with things like bounds checks and checked casts you already have exceptions (or panics), so should you have a way to capture them anywhere on the stack? Are they recoverable in some programs? So should you have try/catch even if you try to make most errors return values?
Another set of questions I have is around reified stacks. Once you have features like generators and async functions, and can switch stacks around, you're most of the way to resumable exceptions. I don't yet fully grok how code as the resume site is supposed to deal with a resume, but maybe resumable exceptions are a reason to keep them.