The intake volume is large and probably too large. It would make a difference to throttle crispness/response but probably little difference to where boost come on. I think of it this way, the maifold volume is say, 1 cubic ft. and the engine is shifting say 120 CFM. Thats 2 cubic ft per second filling the manifold in half a second.
Obviously these are made up figures just to give an eg.

Im going to build another manifold with throttle plates much closer to the valves. it`ll be interesting to see what difference it makes.