As Eric stated.. boost referencing is not needed for roots blowers as the carb is not exposed to positive pressures.. I have built a 350 with a 162ci mini blower and a single 750 holley.
You have way overcomplicated the fuel system needs for that motor. A good, cheap, tried and true mechanical pump like a Carter 172 can easily feed that motor's needs and no bypass needed or boost referencing needed.
1973 RS Z28: 401ci Dart Little M, Littlefield 8-71 supercharger @14lbs boost, Callies Magnum crank, Lunati rods, JE pistons, 7.8:1, AFR 227 Comp heads, T&D 1.6 shaft rockers. Reed solid FT cam (240/250@.050-.523/.542 lift-112 LSA), QFT 750 carbs