Ok, the initial tune was limited to 5psI and 6500rpm - there was no tweaking to do on my part. I’m on Rev 1b and Jason raised the boost to 15psi and I have sent datalogs back him for analysis.
I don’t miss the donkey kick, but will say that the S280 feels a bit softer until you boot it and it revs and produces boost quickly. At 15psi, I’m confident my car is as fast as it was prior to the turbo swap and running 25psi.
The next tune will raise boost and RPM and may or may not be the final revision. Stay tuned - pun intended.