It's actually one (any) base tune that can have different changes within. Basically, you can't have a stage 3 91-octane tune loaded with a stage 3 93-octane tune but you can have the 91-octane tune loaded with a switchable map designed for 93 octane. Each tune can have up to give switchable maps within it but if you aren't pro-tuned or using ATR then you'll just have a performance and economy map of that particular tune.
Short of those that are often switching between E30 and premium fuels, most people won't use the feature much beyond the economy slot.