Using Feature Policy to opt-in, and not just allow

[eeeps]

Right now, in order to send third parties client hints, you must:

1. Allow the sending of specific hints to specific origins (via Feature-Policy) (by default, only the first party is allowed)
2. Opt into sending specific hints (via Accept-CH)

① alone does nothing. ② seems awful redundant, in third party contexts; why would I ever set something like:

Feature-Policy: ch-dpr image-host.whatever 'self'

without then doing

Accept-CH: DPR

?

Can we make ① do ②, automatically?