A CSS property `touch-action: manipulation;` removes the 300ms delay for click events on mobile devices.
Adding this feature is trivial, and there is no downside to adding it:
But it would be good to measure what impact this change has on dwell-time. In theory dwell-time should be reduced by 300ms (though I don't think we measure dwell-time in milliseconds).
If this property reduces dwell-time by any measure for mobile users, that could indicate it's usefulness on wikipedia mobile web.