I don't think it's a good idea. I had a week a while back where I had maybe 2/3 syns each day because like you, I don't have much of a sweet tooth or if I do fancy something sweet, I find that fruit and a muller will do for me. That week I didn't lose and I was gutted so I was advised to 'up' my syns- I was like 'whaaaaaaat?????'.
So the next week I did - and I lost!!
The syns are part of the programme as much as any other part so I'd say definitely use them because then you know you're following the plan 100%.
Sometimes I incorporate my syns in with my meals so I'm not snacking for the sake of it eg, a bit of butter to cook mushrooms in or a bit of tomato ketchup or mayo as a dip or some peppercorn sauce on my steak. I'd rather have a really nice meal with a couple of syns thrown in than eating a bar of chocolate just to eat my syns.