Even though the ingredients are not SBD (of any phase), Sugar Free or Fat Free Cool Whip are
allowed in all phases, as long as you stick to the portion size (2 Tbsp).
The thinking is that, in such small quantities, the sugar won't affect you. Kind of like the ricotta recipe that lets you have something like 3 mini chocolate chips in Phase 1.
Weird, but it does seem to be true.
To that end, it's possible to use whipped cream with sugar in it in the can, as long as you stick with the portion size. It does have saturated fat, but it's not as bad as the trans fats that are in Cool Whip, IMHO. Both have sugar, but the stuff in the can may be better for you than the HFCS in Cool Whip. Personally, that's what I use now. It's hard to stick with a portion size, but I do my best. It doesn't seem to affect me in that small quantity. You can also try making your own whipped cream by using cream and Splenda. There also is one brand that sells a "No Sugar Added" whipped cream in a can (Land O' Lakes, maybe?). It does have sugar, but it's much less than the other canned kind. Hope that helps!