I have the injector overhead to run lower base pressure, and that allows the pump to flow much more, especially as the boost climbs. Yes I am running 32-34 psi at the track on a Hypergear highflow atm.
JH32 have you tried lowering the pressure a little? If you do your pump will flow a little more. Depends how much more you need out of the fuel system. No way I would be spending $1200 to get a twin intank setup going, the Stagea twin 255 setup cost me nothing.
Whatever you do, don't drill and seal the tank lid for thicker wiring, it will definitely leak, I have seen it a few times. Do it properly with an alloy lid spun up on a lathe, then get your own bulkhead fittings and a multi pin sealed plug if you can find one. EFI hardware may have the parts you need.