In #433 (comment) we argued that
Without us actively doing something here (restarting a process, sending a signal, ...) we do not ever actively take control of destructing a TCP connections.
We have followed up with Adam about that, and he states that
r580 and beyond can use SIGUSR1 to force re-establishment of all outgoing connections. (this also reloads SSL certificates, if SSL is in use)
That's great. Let's use this mechanism routinely.