So there is this
issue for task priority you can chime in. For the Flow level though, I think this is tricky because having a priority is a task queue kind of thing where you have a set of tasks that feed into a set of workers, and then you can set a “priority queue”
On the flow level, Prefect isn’t meant to be a task queue (or flow queue) so it will just attempt to start whatever. I know it’s not quite what you want, but have you seen flow concurrency limits?