Huh? Whether or not you put the shifter in neutral has no effect on handbrake (hill) starts. You can still (more quickly, in fact) perform a hill start without also having to put the car back in gear.
And now days, newwer cars have the "hill hold" feature which automatically prevents you rolling backwards anyway.
And now days, newwer cars have the "hill hold" feature which automatically prevents you rolling backwards anyway.