For those who want a warranty-saving tune, they should just do the FP tune. If you're that person, put a period on it and buy it. Based on the only results I've seen so far, it would appear it's actually better than just 30hp. If you are NOT concerned with just a warranty, then pick an octane level that you can afford and consistently use and purchase a tune that exploits it.
All of these tunes are using Ford's algorithms to dial back timing and boost when encountering detonation (or a situation that might lead to problems). And detonation is what destroys engines. A good tuner in either case can adjust certain parameters regarding the intensity of the reaction of the ECU to knock.
Remember that even a vendor has to make money. If there's a market for an "auto-octane" tune, they'll sell one. It doesn't necessarily mean it's better. It's just (possibly) more forgiving, especially if you're the type that alternates between 93 and 87 depending on the price at the pump. Even then, the feedback of this ECU is very unlikely to destroy the engine unless you do something very foolish.