Request with credentials included, but only if they are partitioned #1892

What problem are you trying to solve?

I am trying to use fetch (and the Fetch spec more broadly) to send a cross-origin request where I am comfortable if the request has partitioned credentials, but not unpartitioned credentials. Currently I am forced to either a) omit credentials (hampering utility) or b) include credentials (hampering privacy if 3PC are available and used).

What solutions exist today?

Don't think there are any?

How would you solve it?

I am not an expert, possibly with a new property to sit alongside credentials. Maybe a new credentials enum value?

Anything else?

cc @DCtheTall @johannhof