You’re speaking matter of factly about how the software operates without actually investigating it. Sure, it might be inconsistent messaging but no one is telling me what bug they encountered in this area. It seems to be just a matter of other iX people claiming you should use midclt. I can’t change what other iX employees say on this forum but it would be wise to actually do a bit of investigation of the software instead of relying solely on what is reported on the forums.
So i’ll try to give a bit of help in this area because systemd service files can be quite complicated. We use systemd service files and we also have one for the middlewared service. It has a Conflicts=shutdown.target entry. This means that systemd will send SIGTERM to all service files that have that entry in their unit file definition. In middlewared code, we have signal handlers for SIGTERM. So when we receive SIGTERM, we start shutting down various parts of the middleware stack (ideally cleanly). After timeout, however, SIGKILL is sent by systemd to the process (this is by design).
EDIT: If someone finds a bug with the systemd unit file behavior, then I’m interested and I’d love to know more because that is a bug that we should fix.