No use on empresarial bussiness at the moment because important features no has supported.
I have used OMV for business since 0.2 release.
Docker is a workaround,
No, it really isn't. The enterprise world uses lots of containers.
so many layer between client and server, Proxmox, Openmediavault, disk herachy and Docker. So you need mount openmediavault folder on docker to keep certs and configurations. It is not a good solution to production environment. Proxmox could be supresed, but so many layers same.
I wrote a script that given a location and a couple other parameters, it will update the OMV cert from the command line. You could schedule this to run. You could also run the kvm plugin on OMV eliminating proxmox. This allows docker and VMs on same host.
then, duplicated users?
No. Users created in OMV's web interface are added to /etc/password just like users created from the command line. How would they be duplicated?