This is one of my regular routes (in fact I am in Seattle now).

The lounge at SEA has been reconfigured and there is no separate F section now. However there are some tables in the main lounge that are reserved for F customers seemingly with table service.

As above, boarding tends to be chaotic and crowded. But with F / Group 0 / Group 1 it is over fairly quickly.

The late evening time of the flight means that sleep (rather than food) is the priority of many in J and F.

Other than that, it’s a standard BA F flight.