Like I said, stop getting hung up about season tickets or boxes. Many of those that are waiting for a season ticket will be members now, buying up tickets through members or general sales, similarly those that want boxes (which aren't nearly as profitable as lounges etc) will be taking other hospitality options. The number that matters is how many more beyond those that are buying tickets already. Re season tickets/general admission tickets I don't know enough about your ticketing to have a great idea but the fact that I can buy a hospitality ticket for every remaining game at St James's Park tells me that there's not a huge queue of people waiting to be ripped off.
Anyway, we're just going round in circles now so I'll leave it there.
TBF you're probably right about the income potential of the fan base up here, but still think (as an immigrant Forest fan) you underestimate how much potential in volume there is.
The other thing that limits their potential income is the current location, there's so many pubs / facilities / good restaurants near the ground that they're going to have to provide one hell of an offering to get people to spend more in the stadium.
You can be at the ground after leaving, what 15 mins before, having been at a Michelin starred restaurant, strip club, pool hall, every type of pub or bar you can imagine, soon to be a Hooters...