I'm not saying you're wrong, but to play the devil's advocate, at least consider the fact that adding boost isn't the only thing that makes more power. Controlling the tapering-off of boost (holding it longer), running more aggressive timing, pushing more or less fuel, narrowing a safety margin to within a short-n-curly's width of detonation, etc...these are some typical ways tuners get more power with a given hardware setup, assuming the turbo and fuel system has a high enough ceiling and the induction and exhaust are adequately free-flowing to make more power than the stock tune allows for. A lot of times turbocharged cars aren't anywhere near their full potential on the factory tunes, and big gains can be had with just a reflash because their stock tunes were super conservative for a variety of reasons (reliability, leaving power on the table for use in heavier or higher-priced applications with the same motor, meeting fuel economy or emissions targets, preserving the transmission, etc.). I'm not sure if this is or isn't one of those situations, but it's worth keeping in mind that the hardware may not be the limiting factor if the software is keeping numbers artificially low. Besides, a 4 psi bump is pretty substantial even without factoring-in timing and fueling changes. Dunno if the car can actually produce those numbers with stock turbo, exhaust, intakes, etc., but hopefully it's not too far off.When you think about it, Polestar optimisation in the T6 with K16 is at 14.5psi and only getting 242kw / 330hp
Both Heico and TDI box say boost on their tune is set to 18psi.
Without any hardware changes, I fail to see how TDI box can get an additional 40kw / 54hp. Impossible.