To count as SLD calories, you need the window -- flavor-free calories separate from flavor.   But at 15 calories, it would have a very small effect as SLD calories.

I suspect that coffee may be different from other flavor, since it works well with platinum calories (see thread in tips and innovations section).   For platinum calories, I keep a window apart from other flavors.  Most people doing platinum calories have something comparable to a dose of oil.  But that's not to say it won't help, as fiber has its own an AS effect.   I'm liking chia seeds for that.