If the bike had been dyno’d in the Uk then surely it would have shown up as running lean on full boost?
So if your injector duration is maxxxed out then its either up the fuel rail pressure, or fit bigger injectors. Although in this case some valve on the fuel system was causing the motor to run lean
Not a biker but know enough about car turbo systems and they are complex things , and just bolting on a turbo probably made the thing slower in the end.
Im all for some shed brewed adventures, but why waste time and effort in going 10,000miles and months of work when a morning at a tuner would have at least identified a fixable fault