This would allow for site customization that would not get overwritten. Perhaps it is already handled in a different manner and I have not found the docs for it yet.
On my current setup in extras I have shares defined for my and my wife’s home share and each of our login scripts assign those to a drive letter. This way we each can easily get to the other’s files, yet keep everything separate.
Create a file /etc/e-smith/templates-custom/etc/samba/smb.conf/91shares and put your share definitions or the include in there. To apply the changes just do signal-event nethserver-samba-save or expand-template /etc/samba/smb.conf.