I have to say that I am a great believer in Boost Controller's, but I suspect in this case that there is anothe reason for the boost control problems that your tuner is having.

There is a common misconception that a Boost Controller will work miracles. It won't.

I run a 24psi actuator on mine (consider that a -34 is around 15psi) as that is the only way we have been able to control a fairly stable 30psi.