Stuck with the 98 nDBW/DBC 557P ECU, there are not many options for tunes.
Car came with uncommon "T.A.P. Stage 2 chip", currently running K03/K04 hybrid on stock fuel.

Yesterday, the GIAC PC16 ECU arrived. I want to try the file with 315cc/31lb injectors on 3 bar with the current turbo.

In the works is a K04+ hybrid (it was suggested to me to take the drop in K04-15 as the base, stick a K04-2x turbine in (machining of the hot side to fit) and the the K04-2x cold side. Ideally, would like to find a slightly larger compressor wheel that still fits into the K04-2x cover (RS6 wheel, other?).

With hopefully more flow compared to the K04-15, is the GIAC file/injectors running out of fuel? Limiting the potential of the K04max?

I had tried to find a 380cc file, but no one seems to make them for my nDBW.

But now found an (older) Unitronics 440cc file (and injectors) on a 557P ECU.

Is that too big for a "K04max" turbo described above?

Note: No, I don't want to go elim (on that car).