I am trying to create a very small mask (lighthouse about 5px w and 12px h):
view at, say 400%
command+scroll gets the brush size down to a few pixels and visible over relevent part of image
So far so good, but then as soon as you have started then need to go back to change brush size or erase part, the huge brush-icon-in-a-circle comes up, completely covering the bit of image one is trying to work on.
While moving a slider, the brush icon goes, revealing the effect, BUT there seems no way of either getting the brush icon out of the way for the duration of a whole edit, nor preserving the settings while returning to adjust the mask, nor of unifying a mask made with 2 (or more)different brush settings (and 2 brush icons in the way!)
Unless one can easily get the mask one wants, the whole Local Adjustments thing might as well not be there