Hello,
Since these clients are Unmanaged, all the scan runs in UserMode and so there are very less amount flexibility available.
Again, these features are not available in SEP 12.0 SMB products.
However, I agree these features should have been there.
Check this Article:
About the default protection scan settings
http://www.symantec.com/docs/HOWTO16297
Managing protection scans
Hope this helps!!