Thanks, and yes, I am aware of that. I just don't understand why the current control (used in the just released Polymer 3.0 tutorial!) hasn't been fixed for so long. I assumed that being Google backed, the controls would be high quality and production ready. Even if everything EXCEPT the paper-checkbox is actually high quality, why put such a lousy control in the tutorial? But yes, looking at a demo of the new checkboxes:
https://material-components.github.io/material-components-web-components/demos/checkbox.html , they certainly work much better on my touch-enabled laptop. (they not only function properly, but they also work faster).
Greg