The mask creator opens in a large panel that covers the entire CS interface. Could it open a little bit smaller so that you can still see the CS interface on all sides? This would make it a bit easier to resize and make it more obvious it’s a panel that just opened. Initially I was confused about this and thought it was a new window.
When you resize the panel some of the controls are hidden from view and you can’t get to them (the controls on the right side).
Masked areas are not relative to the image in the editor. When you zoom in/out the masked areas are floating where they shouldn’t.
Original:
Zoomed out:
I see the styling of the UI elements here has been closely matched with CS but it’s still not quite the same. The Stroke Width unit slider is an example. There’s also the blue background color on elements that are hovered, together with light grey text and icons that don’t look good and are too low contrast.
The Stroke Width control has a high amount of padding and it should probably be changed to match the zoom and history controls.