I don't think there is an official line from Cambridge about the use of appetite suppresents, as they are rarely needed. Not saying people don't get hungry, just that if ketosis doesn't knock hunger on the head, then it's unlikely that an app. supp. will have much more effect (except a placebo effect that is).
Appesat is mainly green tea and cinnamon. both of which are allowed. There is a bit of a root of something (can't remember what without googling) which wouldn't be allowed, but I doubt it would be enough to help.
It may be worth trying the green tea and add some cinnamon to your shakes as a half way measure.
You could also try splitting your shakes. I couldn't cope on 3 meals a day. Had to have 6 half meals to keep hunger at bay. Having said that, I was hungry when I finished each shake, but it did go off.
I never remember feeling full or anything, but the hunger pains would go off leaving me in a neutral state until the next meal was getting due.
Aside from that, what about going up to SS+ or 810. You get loads of stuff like quorn. Weight losses are not much less and will make the diet more manageable.
You don't say what BMI you are. This could be an issue as hunger is more likely if it's time for you to move up a plan.:hug99: