It took some vetting, but I finally went with a tuner (UMW) who convinced me that he knew what was going on in the ECU tables, intelligently managed the key parameters, and didn't just globally map values.

I am very happy with the end result with a high degree of confidence that it's all done with my engine's safety a #1 priority, a very usable power curve (far better than stock), and a keen understanding of tuning Porsche turbos in generally from all aspects of engine management (intake to exhaust.)

Price wasn't the cheapest, but it also wasn't the most expensive by a long shot. Value for money is a heck of a deal.