I think that modifier2 holds the user selected PadMode for deck2. Respectively modifier1 holds the selected pad mode for deck1 and so on for decks 3 & 4.
State == 7 is BounceLoop mode, or Loop Roll, how it’s labeled on many controllers.
This is the way for that pad buttons to do different things, in the context of the selected pad mode.
for how it works, I understand that for example, on 4ch controllers, when I change deck 1/3, there’s a modifier state being raised. There are multiple modifiers, and their state.
apparently, it’s an internal thing that the mapping team is setting and it’s very custom and specific for the variety of controllers. Perhaps they have some convention, but that’s not documented, and IMO, doesn’t need to be really - we can figure it out …