[Collection issue] Run a user study on keyboard accessibility issues

[melanierichards]

The purpose of this issue is to collect feedback on accessibility issues we'd like user research on. This issue will collect questions that specifically address the needs of people who primarily/only use keyboard input in order to interact with controls. Please comment as we come across questions, and we can either:

a) Seek out prior art/studies on these behaviors b) Design a user study to address these questions once we have enough behaviors we want to verify

For accessibility questions unrelated to keyboard input, let's start a new collection issue. It may be the case that we can combine issue buckets for a user study, but depending on the nature of the questions we may want to recruit a different set of participants.