I would like to see the shared folder location to be customisable from the gui. It shouldn’t be a really big change in the gui code since the previous line in smb.conf is a line with customisable text from the gui.
My specific needs are a bit more complex (Samba VFS ) and I’ll come back to that later when I get something working. This was just something I noticed playing around with Samba looking into VFS.
Shared folder location is fixed to simplify automation tasks and backups.
You’re free to move it using a template-custom, but bear in mind that some scripts may not work.
Also remember to add the new directory to the backup.
By the way, when you are ready to share your findings, maybe we can suggest something to fit your needs! 
It might be that I have the wrong idea about Nethserver, but to me Nethserver is oriented towards providing network services like DNS, DHCP, AD DC, SNMP, mail, etc. Nethserver isn’t oriented towards providing large amounts of storage, as indicated by the fixed location of the shared folders on the boot drive and the lack of any kind of way to deal with storage mediums. When you need any reasonable amount of storage via shared folders or use the Samba users home folders it needs to be stored elsewhere, not on the boot drive. Be it a separate drive in the server or some form of network storage. For network storage the backup isn’t Nethservers problem to fix, if the storage is on the server there are probably some simple ways to automatically update the needed backup paths.
In my case I’m trying to get Nethserver/Samba to handle a Ceph storage cluster. So either via Samba VFS or mount the CephFS in Nethserver and then a normal Samba shared folder.
You have a great usage scenario 
, a bit outside the normal usage of NethServer. 
But I guess you can mount your CephFS directly on /var/lib/nethserver/ibay. What do you think?
For me it probably wouldn’t matter where I mount CephFS since it’ll be shared over the network via Samba.