Over the last few months, in preparation for Apple Vision Pro, I started a quest to find a good portable keyboard + trackpad setup for the headset. After testing out a wide range of those from the market, here are my findings. Hope it helps people looking for the same.
The impression is based on testing out the keyboard/trackpad with iPadOS, as it shares the similar infrastructure for external input support as visionOS.
After testing on real hardware, visionOS disabled support for any non-Apple trackpad... So feel free to ignore everything about non-Apple trackpad here.