The L helveticus in kazu introduces different proteases and peptidases when it is maturing which helps to add a sweeter, more gruyere-like character to the cheese. It also is helpful as a protectorant because it will consume additional sugars such as galactose, in addition to lactose. What does this mean practically? It means your typical mesophilic mix with l helveticus will have more nuanced notes in aged cheeses, like an older cheddar.
Adding a thermo culture to a standard meso is a fairly common practice to craft flavors and produce distinctive cheese. Around here in WA, beecher's does it in their flagship aged cheddar.
