Investigate adding knobs for explicit-exit-notify in OpenVPN
explicit-exit-notify looks like it can greatly speed up recovery time on OpenVPN process restarts and potentially HA server installations.
In UDP client mode or point-to-point mode, send server/peer an exit notification if tunnel is restarted or OpenVPN process is exited. In client mode, on exit/restart, this option will tell the server to immediately close its client instance object rather than waiting for a timeout. The n parameter (default=1) controls the maximum number of attempts that the client will try to resend the exit notification message.
In UDP server mode, send RESTART control channel command to connected clients. The n parameter (default=1) controls client behavior. With n = 1 client will attempt to reconnect to the same server, with n = 2 client will advance to the next server.
OpenVPN will not send any exit notifications unless this option is enabled.