As it’s not designed for that, I’d say pretty off for heart rate. Movement probably close, but as you’re not working out with it where you’re looking for high accuracy in heart rate and motion, probably good enough for use without another option. I’d think upper arm may be more accurate than ankle. And avoid the risk of kicking your own watch if you stand up funny uncrossing your legs.
The only case where you do not have to double click a confirm id for touchless transit systems. But it is an option you need to enable. It just gets you through the subway turnstile or bus boarding a bit faster. Obviously it depends on your transit system and country (even city), and of course if you even use a transit system.