I also noticed the same after your post, but then I tried in a different method, I tried to use the mouse's scroll button to increse and decrese the sizes
in this video I tried to show how I did it
You can Cmd-drag inside the Size field instead of the slider. That'll always give a 1-unit increment. Shift-Cmd-drag in the field will always give a 10-unit increment. (Cmd is for Mac - use Ctrl, I guess, on a PC.)
Thanks for pointing out that useful way of changing the brush size. Unfortunately I think it goes too far the other way ie. it changes size too slowly . Instead, the suggestion from conroy (see below) works a lot better as it alters the size in increments of 10.
Thankyou very much though!
Thanks conroy. In the absence of an ability to change the scale, being able to increment or decrement by 10 pixels at a time will be quite useful.