Not due to the tin-canning/flex, the gasket got unseated at a weak point where the 2 parts of the manifold bolt together and it was under lots o-boost. 20+psi.
I picked up peak gains 30-35rwhp throught out the curve from 3000rpms on up my turbo setup. An im currently running 16psi no problems.
The tin-canning or flex is just due to the design the manifold its taller and 2 piece design which contributes to it. Only Under just a quick rev where the car goes from full vac to zero back to full vac the top pulls down and goes back up as the sides flex.
Its actually hard to make it do it i, have done extensive testing on the dyno and street observing it. It has to be a quick short rev to get the lung effect. It does not move at startup, part or wot, or normal driving, you have to try to make it do the flex, its not like it sits there and does it while you are driving or anything.
Anyway I have had mine on for about 6 months now, looks great, was a great price, and made good power on my setup, love it.