You've had excellent results and I don't know if your coach is a good or bad one, or was merely brainstorming the options that could be tried. I would suggest you try the ones that keep you with low carbs first (instead of all restricteds).
When I added more protein I lost more - I always had the 8oz. When I "skimped" on any of the protein, veggies or oil I did NOT do as well. The plan is already very low calorie, and for me (very personal experience) there were days when I was traveling and had two restricted and those weeks the loss was strong.
I'm the same height as you and was at almost the same weight you're at.
Celebrate your loss so far, and keep a really good log of how the changes you try affect you - just don't change too many things at once or you might not know what worked