In the video at around 6:45, it is mentioned that adding Shift is basically equivalent to using the Smooth brush. It does produce a smoothing action, not always what I expect.
A. Does Shift + [brush] use the size/strength of the original brush, or of the Smooth brush, or something else? All the brushes might have different sizes / strengths.
I tend to get lots of different results with Shift – I tend to go for Smooth brush instead, for predictability.
B. Follow-up: Is it ever advisable to set “unified size and/or strength” on the brushes? I see “unified size”, not sure if that is the default or if I changed it. I know that is kind of advanced, but maybe it could help a beginner?