Nice one I didn't see the FMIC at Comb.

FSE boost valves are crap, totally pointless & a waste of a 100 quid.
Not strictly true, a FSE Power Boost valve is nothing more than a rising rate fuel pressure regulator. Bosch rising rate fuel pressure regulators were fitted to the likes of integrale, Cosworths etc as standard.
There purpose is to increase fuel pressure when the car is producing boost, this increased fuel pressure overcomes the increase inlet pressure and increases fuel flow when its needed.
Some turbo cars like R5GTT's Uno etc which were by no means as well developed like the cars I mentioned which were designed as homologation cars for WRC have these but normal or fuel pressure regulators that may not incrase fuel pressure quickly enough or high enough, by fitting an uprated FPR can have benefits especially if increasing the standard boost pressure that the OE regulator can legislate for.
On a N/A car, I can't see any real benefit unless running lairy cams and running to high rpms.