I wish we could return to a Wii U like functionality where the switch could be used as a second screen when undocked. That was a really nice feature in games like Zelda where the controller in your hands displayed the inventory or a map.
Might be possible if the Switch 2 contains a "cast" feature, but the cast landscape may be too incomplete and fractured (AirPlay, Chromecast, Miracast, etc.) for Nintendo to bother with that.
Couldn't the handheld pair with the dock with whatever protocol they want, and the dock is wired into the TV?