I DON'T NEED AND DON'T SUPPORT NO (watch this double negative for emphasise) NEW DIMENSIONING TOOL IN SKETCHER!
Sketcher has all I need to highlight diameters where I am too lazy to do simple maths. I can devide by 2 or double a value or use expressions. Why should I want half dimensions in Sketcher? (Please don't answer this one. I know the answers already...)
BTW
It's your choice, you are the designer.