I have to say i agree with Circes.
Stopping syns has never worked for me, but i tend to be okay if i only have 5 a day and save the rest.
I think it has to do with the fact that having no syns will not be sticking to plan, you may be consuming too few calories causing your body to store your food out of fear that it wont be getting enough to function, therefore when you finally do have your syns at the weekend (even if you dont go overboard) then your body will store that too causing a STS, gain or smaller than usual loss at WI.
You can only try hun and see if it works for you, but maybe try having half your syns and saving the other half.
xx