"4.12 Immersive time limits

User Need 12: Users with cognitive impairments may be adversely affected by spending too much time in any immersive environment or experience, or may lose track of time.
REQ 12a: Allow the user to set a time limit for any immersive session."

https://raw.githack.com/w3c/apa/6d5bf713d9d7c65ecda104c213ad47b0e98cfbe1/xaur/index.html#immersive-time-limits

Thank you so much for bringing this User Need to light.

From the perspective of writing requirements for this, there is not enough information to design demo solutions or related user research. What are the adverse effects? Will the users themselves be aware of these effects? Is it appropriate to allow the user to quickly return to the environment or to turn off the time limit? What is the degree of the adverse effects, as this is needed to inform where such a setting needs to be presented, or even if a time limit should be the default setting. While I can guess that this will vary user-to-user, it would be helpful to have some idea of the lengths of sessions that are problematic, as the experience should be designed so that at least one task can be accomplished within the shortest likely-to-be-needed session length.

A link to any type of source document that outlines what is known so far would help tremendously.