Do you think it will ever post a problem to have the schema cached? e.g. what happens if a field is registered after the schema is cached?

Do you think it will ever post a problem to have the schema cached? e.g. what happens if a field is registered after the schema is cached?

The tests seem to reflect that concern, as the additional fields aren't registering anymore. The registering could be changed to just work with the object property though. I mainly think using schema as an object property would be a problem with internal requests, via batch processes.

Do you think it will ever post a problem to have the schema cached? e.g. what happens if a field is registered after the schema is cached?

This will already be a problem, since the schema won't be exposed to the client, and will be inconsistent internally. I think having internal consistency makes it more obvious if you're hooking in at the wrong point.

I think having internal consistency makes it more obvious if you're hooking in at the wrong point.

Maybe all of these schemas should be generated and cached at the same time (on some hook) to ensure there's internal consistency from hook to hook.

I'm pretty sure it is consistently generated right now on rest_api_init, since the schema is passed into the route registration. See also #2694.