Over 28 days, I really don’t think it will make much difference, you’ll still lose a ton of weight.
However, speaking purely anecdotally, I have noticed a small difference on the days that I include 150ish cals worth of creamer. It could be just a coincidence, but I definitely tend to lose slightly more weight on fasting days with only black coffee/tea (ie. 0.4lbs difference). I try to avoid the creamer whenever possible, but it really makes it MUCH easier for me to fast, so it’s just a trade off. Realistically, there’s no way that 150cals of creamer should make that much of a difference per day.
If I were you, I would just try alternating creamer with black coffee days.