I'd use a feature pattern instead.
Well, isn't that cool (good thing I checked). I just tried to drag it out of the way and while it acts like it is letting you drag the dimension off the circle, it will never actually move once you release it.
You can use the "Select Other".
But really, unless there is some situation where you absolutely can not use a feature pattern I would avoid the sketch pattern.
Not seeing a selection to change thew visibility on the dimension level.
Not seeing that this is possible.