Do you have any examples of similar feature in other apps?

I’m not using Artstudio Pro anymore. Tried and dropped. The redesign with fixed tools on top isn’t convenient. Why there isn’t a floating toolbar at least?

I was explaining that few times. Generally i didn't like 3-modes solution from version 2.x (Normal, Painting, Fullscreen). Besides bottom and right edge should be empty, so user will not touch any button by mistake with his palm.
So we have the space for controls only on the left and top.

I agree movable bars is also a good solution, maybe we will implement that in the future, but now we have to add some missing features, so bigger UI changes must wait.

I suppose you pressed Q key, which is a default shortcut to enable/disable Quick Mask.
You can change that (and also check other shortcuts) in Preferences > Interface > Keyboard Shortcuts.

Ok, it will be added in the next minor update.

There are much less Mac users, so Mac forum will be rather empty.

Each stylus producer i know provides pressure/tilt pressure curve in Mac stylus drivers. That's why we don't have pressure/tilte settings in Mac version of Artstudio.

You can reset single brush - Long Press the brush and pick Reset

You can also reset the whole group - Long Press group and pick Reset Group