If the emissions system ever imposes a problem for long-term performance, then we can install an electric exhaust cutout valve to dump exhaust. The stock exhaust system won't be blocked out (just reduced flow) to keep the sensors happy. Wire the exhaust dump to WOT pedal or 80+% pedal input (depends on performance vs. throttle mapping), or to a dashboard manual switch (or both).
A decent looking electric cutout valve with a manual rocker switch can be found for $100-120 USD if I remember correctly. Welding not included.
The catalytic converter might however be placed very close to the turbo like the current MKV PDs, potentially making exhaust valve placement difficult.
Anyway, the CR would be a cool swap motor for car projects.