So what narrative did you buy in to?
Personal experience, backed by empirical evidence. I've been using supplemental fuel systems like methanol and/or propane injection on boosted applications for over two decades. That's with a huge background in data logging and tuning multiple platforms.
So yes, it works. Tuned or untuned. A progressive control module and the Closed Loop system (very responsive) in these cars are a very capable pairing.
Tuned will net a better gain. But, as an "octane booster", to use a colloquial term, it is very effective at preventing the volatility of relying on suspect low-octane premium pump gas.