You can set breakpoints on flow runs. I don't believe there is a simple way to do that forynchronization points. As for remote tools, we do have an example https://github.com/PrefectHQ/prefect-recipes/blob/master/examples/integration/parallel_flow_run_with_kubernetes_and_snowplow/main.py that shows how to run a flow in a Kubernetes cluster using a third party library called Snowplow but I don't believe there is a way to set a breakpoint right at the point where it is submitted to the Kubernetes cluster.