The silicone case does go around the button, so yes it would make it harder to press.
The cover has a big opening around the heart rate monitor, but because it has some thickness it would reduce how hard the HRM presses against the skin. I don't have any info on whether that would affect readings though.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
The silicone case does go around the button, so yes it would make it harder to press.
The cover has a big opening around the heart rate monitor, but because it has some thickness it would reduce how hard the HRM presses against the skin. I don't have any info on whether that would affect readings though.