I've seen some testing to show that all out naturally aspirated race engines can make more power with injectors outside the inlet's bellmouths, but I haven't seen anything to suggest turbos get any benefit from it. It used to be the way to go back in the 80s for your turbo car though - add an extra injector inthe plenum and a microfueller to controll it at high load. But we've come along way since then. Plenty of very powerful turbo race engines just use a single set of conventionally placed injectors. And in an IPRA restricted turbo setup, where you'll only ever make about 250rwkw through the restrictor, it's simply not neccesary. It can be done easily with a single set of injectors conventionally placed near the port face. The second set of injectors, fuel rail and wiring are just extra weight and complexity, with more potential points of failure or headaches. Imagine if it starts running a bit rough at a race meeting - you've now got a much more complex troubleshooting proceedure reducing the likelihood you'll find the problem when the pressure's on in the rush to make the next race.

I think the same goes for the long manifold. A conventional manifold design half that length (and weight) should be do the job just as well and be easier to work on. You've got an inlet restrictor limiting power, all out manifold designs simply aren't needed to make ~250rwkw with forced induction. Nor are long inlet runners - the 30psi boost will take care of the torque/midrange. But to take advantage of your smaller capacity, you'll need to utilise all the revs you can extract through the restrictor - that's where your advantage is. It should be able to make power to nearly 9000rpm through the 36mm restrictor.

Don't get me wrong, the power your making is very impressive, particularly on stock pistons! But I think the way forward is making power up around 8500 - cam selection and timing, cylinder head etc, rather than getting bogged down in trickier inlet manifold designs and experimental injector placement.
EDIT - I missed your last post while I was typing that. Its no real surprise to see you're already working on a better bottom end to be able to use the revs...

180rwkw makes for a very fast Datsun 1200! And your would be alot lighter than the CA18 powered one I had, so faster again. But the 230rwkw mine made on 1.5bar and avgas was a completely different car compared to the detuned 185rwkw it made on 1bar and pump gas.