For sure! Unfortunately, he has fallen into the same trap that almost all new GN owners do. "Gotta make MORE power!! now!!"
Blown head gaskets are in his immediate future.
Heck, it took me over 20 years of tuning practice on these thing to learn what can be done and what can not. I've got the tuning knowledge and correct parts in combination that I can run just over 20# of boost on 93 octane with no alky. I've never used it and don't see the need.
One must take the time to learn their car, it's combination of parts, how they work, how they don't work, etc.
He's already starting out "in the hole", by being UNDER injectored for the turbo and other parts he has. But, replacing parts is part of the learning process. I hope he can do his own work.