If you install v-one for the CS757, it will provide spoken v-speeds, spoken flaps, slats and spoilers, and CofG.

Also, the default FSX load manager can provide a CofG % indication (from memory, so do please check: count lines from top down to your present CofG, and divide this by 32, then x100).

I completed an immaculate flight in my CS752 tonight, VNAV and LNAV from start to finish. Brilliant!