Doubtful. Remember, the faster you go, the more drag, the greater the fuel burn. Likewise with lower altitudes. Different operators might use different speeds for the same type of aircraft. When computing ETPs, dispatch doesn’t have to include time and fuel for the turn or decent, nor APU operation. Use your FMC fuel calculations to the fullest extent. Sometimes dispatch planning can overlap “over water, extended overwater, flag and/or ETOPS” requirements, resulting in “re-releases.”
Fire suppression for every aircraft must be rated to exceed the Area of Operation, e.g. 195 minutes for 180 minute approval.
Some companies grant captains greater authority and latitude than others.