Am I missing something??
As I don't think there's a problem
We have approx 500 season tickets holders with around 150 choosing to stand.
There 350 choosing to sitdown. We've around 1400 seats available to sell. Take out those 350 current ST holders still leaves over 1000 seats to sell.
If somebody new arrives, we can either suggest an "spare" sit or recommend they choose a seat that isn't a current ST holders and to me "solution"??