Where a request's priority comes from, when it takes effect, model overrides, and defaults.
A request's priority can come from an incoming request header or from the user's profile. When user profiles are used, the proxy caches them from CosmosDB into memory, refreshing the cache every hour, and matches each incoming request to a profile to assign its priority.
See Priority Levels for how priority values are structured and what they control.
The proxy resolves the profile before admitting the request to the queue. It assigns the mapped priority when the request is enqueued, so the value affects dispatch order as soon as the request begins waiting for a worker.
Yes. A user profile can specify a model override. The proxy rewrites the original request to use that model before forwarding it, so model selection can be controlled per user without requiring the caller to change the request.
The proxy uses DefaultPriority when it cannot override it.
See User Profiles for profile structure and loading.