ExecStopPost should allow us to clean up (docker kill + docker rm) even if the ExecStart (docker run ..) command failed, and not just after a graceful service stop was initiated. Source: https://www.freedesktop.org/software/systemd/man/systemd.service.html#ExecStopPost=
It seems like it doesn't cause any issues for any of these services.
Also includes the dashboards for Synapse and for Node Exporter. Again has only been tested on debian amd64 so far, but the grafana docker image is available for arm64 and arm32. Nice.