Thanks for the clarification Ian. I understand what you are saying. I suppose the rule language inconsistency is just something I picked up on, and is not an issue in general.
I really am looking forward to racing with NASA, and GTS in particular. I have been away from the track longer than I wanted, and miss it very much. When I looked into my options for returning, GTS was the hands-down winner as far as simplicity and fun-to-run. I can start small (slow) and work my way up, if and when I choose, without having to worry about my car being disallowed due to performance upgrades. It looks like NASA came up with a great system.
If you can make an adjustment to output power between the checkered flag and impound, the mechanism for doing so needs to be declared ... if that's a switch on the dash, you have a means of opening the hood and adjusting a boost controller while driving your cool down lap, or have a remote control fob for it (Revo software). For the most part, this means anything limited to existing within the cockpit.
Do I declare my manual boost controller? No. Do I declare my ECU software even though it requires a laptop and connectivity to the OBD-II port? Yes - the engine parameters can be adjusted from the cockpit. If tech sees me at my car in impound with a laptop, they know I can be making changes that would alter compliance monitoring. If you choose to declare an under-hood switch, knob, adjustment valve, it certainly wouldn't hurt.