Your "not approoved method" is actually the preferred method now. You make a mark on the quadrant when the fuel flow lever is at 29degrees (engine off) on the FCU quadrant I think. You do a check start and thats your start to advance to your mark then press the button. In the manuals now and service letter/information letter frome TM/EC-not certain.
That however is for the B, BA, B2 only. The B3 you switch the batt on, fuel pump on, chk according to the checklist and then simple switch the engine on with a switch. All done via computer until ground. At ground turn the twist grip to FLT and again the computer does it for you.