Casa Par 61.085
61.085 Definition of flight time as co‑pilot for Part 61 A person’s flight time as a co‑pilot is any period, during flight in an aircraft that, under these Regulations, must be flown with a flight crew of at least 2 pilots, in which the person is performing co‑pilot duties other than as pilot in command under supervision.
Note: A co‑pilot is a pilot on board an aircraft in a piloting capacity other than the pilot in command or a pilot who is on board the aircraft for the sole purpose of receiving flight training: see the definition of co‑pilot in Part 1 of the Dictionary.
Takeoffs and landings don’t mean anything in logging flight time as that’s only for the PF to log else you wouldn’t be logging and PM sectors you do. Key phrase co-pilot “any period, during flight.” The Note has a clarification of on board in a piloting capacity other than PIC.
If your SO time doesn’t count as co-pilot then you are not acting as a co-pilot when on the flight deck and therefore a 2 crew aircraft is operating single crew.
Bunk time does not count.