It is not possible to run run stateMachinesSnapshot from the shell
It fails with
RPC failed: java.lang.IllegalStateException: Jackson didn't provide serialisers for [actor]
Since flow watch doesn't return checkpointed flows, it only displays them once there has been a state change, it is impossible to even see what flows are running through the shell.
We should add more sub-commands to the flow command rather than expect people to use a mix of RPC and human-oriented interfaces.