Unlimited year/model

Please forgive me if this is in the wrong section. Just unboxed MPVI3 tonight and got everything going. I'm pretty new to tuning, with just minor exposure years back, but starting to teach myself with this. I'm messing around with a 2004 Silverado, and I have 3 different engines I'm going to play with, all Gen 3 with their own PCMs, and I have some other random PCMs hanging around because why not. Should I just jump in and get unlimited year/model? I'm a little foggy about how that works.

Well the Gen 3 truck has paid for itself already. Paid I think about $1,500 for it.

Generation group licenses are not offered anymore.