I was just going to say this. It has to have a CARB sticker. No CARB sticker, no pass. Passing a smog test in most US states typically uses on-board telemetry combined with a rear-wheel dyno. Most smog shops won't touch vehicles that lack OBD2 but still require smog tests every 2 years. Also, I'm unsure if smog shops still use an external NOx/CO probe like ye olde days or rely entirely on the vehicle to be non-VW "smog mode" honest.
That's a very CA viewpoint. I moved from CA to NC and as long as the onboard computer isn't throwing a code and your emissions stuff (appears to be) in place they don't care. I have two vehicles that are tuned and they pass emissions no problem. They can see this (different means per manufacturer, I think BMW throws an invalid checksum and Ford does it by key trigger count or something) but since the vehicles are still blowing clean it's fine.
We just had a few counties discontinue emissions checks and now only do safety checks up to 30 years past which they don't inspect at all.
Keep in mind the EPA is cracking down HARD on businesses that sell any kind of "tuning" or "delete" device, handing out fines in the millions of dollars and shutting down businesses.
It's all well and good to say "you can get away with it", but the businesses selling these products can't.
You're projecting California onto the entire country. Many states thad mandate 50-state compliance for new sales stop caring after and most of them only do a plug in test anyway. Many states don't test at all.
Vehicle mods exist in the same sort of patchwork of "illegal to various degrees but nobody cares" gray areas that weed does.
At the end of the day enforcement is capped by political will.
I can see a future where auto manufacturers lobby to make “unlocking” features highly illegal due to the DMCA or some other.