Why not just offer 2 tunes: One that complies with all their nanny regulations, and one for off-road use?
Make the end user sign a waiver stating that their vehicle will only be used for off-road applications, and the company washes it's hands of any liability.
I had to sign a waiver for the tune on the NSX.
If it’s emissions only, a GTR on stock all seasons and tune only has run a 10.6 through factory exhaust. Hosed long the factory cats last like that, well who knows.
A 991.2 or 992 tune only will run 9’s through factory cats.
All the FBO GTR guys still can run about the same and can probably add a MP with some sort of dump / blow off setup and still make all the noise they want.
It’s the turbo swap crowd and higher that will need to go to Ecutek now or motec.
The M cars tune only have been running low 10’s through factory exhaust for years.
Man search YouTube for the doom and gloom from the Subie guys - world ended according to them.