porting depends very much on the spec and end goal off the engine, there's so many variables to account for when porting a head. If you were to run 350+ would require maxing metal removal that the gaskets would allow, the exhaust side on the 4e head is shocking, can open it up to 33mm (gasket size) from the standard 29mm, this would require opening the throats considerably, take up to 5mm out the dividers, etc etc.. However inlet side only requires minor work, as you say this side requires only shaping and smoothing. Head should be ported to the spec off the turbo/ engine theres so many variables to consider when talking about porting. Mine just needs smoothing and shaping off the ports to aid the flow off air and restrict it less.