I've recently reduced my metformin from three 500mg/day to two 500mg/day. Metformin's half life is around 6 hours so I take one with breakfast and one before my evening meal - this satisfies me that I'm covered for all three meals and an evening snack - if I'm tempted.
Do you normally eat breakfast? Breakfast as well as one metformin might counter some of the effects of DP.
Someone following a low carb diet will be able to help you with when you should detect ketosis better than I can. As for getting that full feeling, beans help me and they are a good source of protein.
Regards, Tubs.
Edit - Just realised you're on Metformin SR which, I think, is effective over 12 hours - wouldn't it be better then to split the dose one at breakfast and one with dinner to ensure that you've 24 hours coverage?