I know it's not officially supported nor is it best practice but most devices do support partial updates, i.e. if I just clear and redraw parts of the screen this will work without problems (only if a message popup is shown this may lead to short artifacts).
My watchface needs to execute a lot of font loads and unlaods so I do only update on part of the screen after another on most devices and on some devices I always redraw everything because some devices do need this because they do clear the canvas before each redraw.
Question
Is there some way to detect which device does support those partial updates and which not, this means which device does clear the canvas on each redraw and which not?
I know already which device does and which one not, but whenever I add support new devices I currently do wait for user feedback and only afterwards I know about such a behaviour...