HG install techniques

[Jakey]

So from what I understand, the whole purpose of coppy spray is to simply provide a supplementary adhesive force between the head and the block. This then allows you to simply run greater intake manifold pressure with a decrease change of blowing your headgasket. Couple this with a nice set of ARPs and you'll have a hell of a seal. What I don't understand is why is the the coppy spray necessary when people all over are running stock Mitsu headgaskets, no spray, a set of ARPs, and pretty decent boost pressures and not having problems; what am I missing here? Am I not correct with my above information?