Otherwise you’re stuck with the default pointier mappings, which only uses one controller while the desktop one can use both.

That reminds me of another random issue I had: I can't point using one controller and use the stick for the other controller to scroll. On the Steam Deck, it feels very natural to point with the right touchpad and scroll with the left touchpad, so I figured it would feel natural on the Steam Frame to point by aiming the right controller while moving the left stick to scroll. But any time you move a stick, that controller becomes your pointing controller.