If you have 3 tap regions already adjacent before enlargement, how does enlarging them help? Like the w, a and s keys on a keyboard. Making the regions larger will just make them overlap.
Idk how apple does that exactly. I’d just voronoi it if they intersect and tap outside-ish, just like I do with hn vote arrows.
Anyway my point is that you can design interfaces denser than three buttons per screen and they will work. Not that a 5mm block with 8 links in it is a good button bar.
