Many users are confused by the marching ants previews (a feature request for 0% treshold of selections to be added here) but so not seem to notice the Quick mask button or to know their Q shortcut.
Select and Mask has an entire array of masking previews: on black, on white, quickmask style(overlay), onion skin, that should be available for each and every masking/selection tool.
Please add all the preview modes in the option bar, but especially in the Contextual Task Bar!
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