But that wont change the response of the engine to be honest just driving input.
Its a hard trade off between response and drive ability and also a little tricky trying to decide where you should take the weight from and where to keep it. You could go all out and with Titanium internals, knife edged crank, lightweight flywheel an so on but with hugely reduced inertia from the lightweight parts it would be a ball ache to drive on the street and in traffic IMO.
ITBs alone make a huge difference in response on there own. Bumping the compression up would help with off boost drive ability and help it pick up better.
Just my opinion though