Not everyone has the same number of fingers. What can we do to make things work well for these users? We should probably solicit input from affected users when tackling this problem.

Some concrete concerns:

• We should enable applications to be written such that users may get a hand representation faithful to their own, if they so wish
• It should be possible for applications using gestures to be able to support fallback gestures in cases where some fingers are missing

Some of this probably requires devices/backend APIs to expose more information (or configurability at the OS layer). Filing the issue now as a tracking issue so that we don't forget about it.

(h/t @mcclure for reminding me of this and pointing out specific concerns)