That seems like a way to find optimum timing for an engine that is octane restricted. Also the timing would be known as optimal only for the rpm and load it was set at. A motor can lose power from too much timing before it goes into detonation. It depends on what the octane requirements are for the particular engine and the octane of the fuel being used. The timing number (lets use 30 degrees) is assuming that the timing marks have been checked to be accurate along with the tdc mark. Also most engines won't maintain 30 degrees through the entire rpm range even if the timing is locked. So 30 degrees happens at a particular rpm. A motor with 30 degrees at 6000 and 24 degrees at 3000 may not run the same as a motor with 30 degrees at 3000 and 24 at 6000. The best way I know is to see what the timing is in 500 rpm increments then sweep the motor for best power under full load then adjust the curve accordingly. That will get you pretty close to optimal full load timing.
