For the past 16 years driving a MT, I've never downshifted from 2nd to 1st in normal driving or even open highway sprinting.
Living in the city of hills, I still don't downshift from 2nd to 1st. I go from 2nd to neutral to 1st. Don't use the ebrake either. Learned from the start to be fast off the clutch. In fact, I thought it was a no-no to downshift into 1st from 2nd.
6500+ miles driving with this philosophy and the tranny and shifting remains stable and smooth (even better with the Kartboy and bushings!).