There is one caveat in that fix and it's this # This configuration file is auto-generated. Which implies that if there is an update then that file will be overwritten and you will need to do it again.
Edit: Look at post 10 I'm sure he's a developer for Emby and post 20 by @gron who has made some modifications.
I'm not a fan of having a bunch of temporary workaround scripts and services lying around, so I looked into what I can do with the systemd unit in question
You could also override the entire systemd mount unit so that auto-generation doesn't change anything in the grand scheme of things. Of course if OMV does change something, you'll need to edit the override manually.
I'm still not sure which changes caused all of this in the first place