> And many of the hung queries wouldn't even show up under traces in their observability dashboard

How did you work around this problem? As in, how do you monitor for hung queries and cancel them?

> D1 reliability has been bad in our experience.

What about reads? We use D1 in prod & our traffic pattern may not be similar to yours (our workload is async queue-driven & so retries last in order of weeks), nor have we really observed D1 erroring out for extended periods or frequently.