Hi!
Most often what I want to do is scale a selection in a sketch down or up around its center. Having to pick a point as a reference often doesn't work and is annoying, requiring me to create one just for this purpose.
So either adding a check box (and the settings of it should be remembered!)
or
have a center point appear (as normal snap assist) when you move the mouse over the sketch.
It would also be nice to be able to select say one of the corner points or edge center points in the same way.