Yes, remove it from your patch configuration and delete the file. Perhaps I need to clarify this in the readme, because the BOSS warning doesn't appear to be clear enough either.
Thank you.
The boss warning is:
"Note: Not need for 'DLCThievesDen - Unofficial Patch.esp' v1.0.7+"
so I supposed that while it's not needed, it wouldn't cause problems. Since OBMM doesn't allow you to delete the file since it's part of an OMOD, the easy solution was to leave it there deactivated. I had forgotten about the fact that the wrye bash also can import data from deactivated plugins.
Perhaps the warning should be:
"Delete this file! Causes problems and is no longer needed with 'DLCThievesDen - Unofficial Patch.esp' v1.0.7+"
(I've learned the hard way that instructions have to be clear and should not leave any room for interpretation at all.)
Is there a reason why the SSSB file should not be removed from the Unofficial Official Mods Patch Omod?