For 19 queries where the expected top-1 source was apple-docs (weight 3.0), the actual top-1 was always apple-docs:
concurrency, actor, Hashable, Sendable, Result Builders, Property Wrappers, async await, Generics, Observation, Optional, Protocol, Closure, Color, Navigation, Button, Typography, Materials, Privacy, Widget.
The source-weight machinery is doing exactly the work the design intends for the apple-docs-canonical case.