We succeeded to implement samba 4 (version 4.8.3) on fvdw-sl.
By setting a basic configuration, system files size is enough small to be included in the firmware image (27MB instead of 110MB with a standard configuration).
On next version, you will be able to choose between the current version (3.0.37) and this upgraded version 4.8.3.
Badly, this feature won't be implemented on tiny platforms (nwsp1 or SPD 8020): samba 4 requires too much memory for these platform types.
SMB2 or SMB3 protocols may be used with your samba client such as Windows 8 or Win10. We added also an option to disable SMB1 (but you should keep it enabled if you have old samba client like 9x, XP,... Vista)
SMB3 allows to improve read speed (max: 55-60MB/s) and sightly write speed (max: 18-20MB/s)
Please to note performance is still better with version 3.0.37 if you need to use SMB1.