All B787’s have two bunks and really a useless seat in the overhead crew rest. For simplicity sake, flights over 12 hours require 4 pilots. Since the seat upstairs is not compliant with FRMS guidelines, First Class seats are then blocked. Usually 1A and I forgot the other one to be honest. Flights less than 12 hours only require 3 pilots thus no Polaris seats are blocked for crew.

B772 have the Pilot crew rest in the closet front left behind the flight deck. Depending on the flight length, a single First Class seat is blocked for crew use, usually 1A.

B773 is the only aircraft with proper bunks and seats compliant so none of the First Class seats are blocked.