Handheld, or best on the lap. Has some nice zoom and scroll functionality.

Looks interesting, but uncomfortable to me. Could use at least some https://en.wikipedia.org/wiki/Sugru or similar.

While I like wired input while it's on the desk, I'd rather have that wireless when handheld free in the air, or on lap.

Because then the cable is more likely to be a hassle, or leading to restricted movement to avoid that hassle.