Two programs can run the same renovation, with the same budget and the same contractor, and come out of it very differently. The variable is sequence.
Phasing gets treated as a construction decision, handed to the people building the thing. It's actually a revenue decision, and it's made early, usually before anyone has asked what each option does to a season.
Taking the east side out first is a different year from taking the north end out first, if one holds more inventory or more premium. The construction sequence rarely accounts for that on its own.
Two phases running together finish sooner and hurt more. Run separately, they stretch the disruption across more seasons but keep more of the building open in each. Neither is automatically right.
Some work can only happen between seasons. Identifying it early shapes everything around it. Identifying it late forces compromises in both directions.
Added seating is worth most where it protects premium inventory or keeps a sold-out section selling. Worth least where it fills space that wasn't generating much anyway. The phase plan determines which situation you're in.
What does each phase remove, in seats and in premium, and what is that worth across a season? Can any two phases run together without doubling the disruption? Which work genuinely requires an off-season, and which only prefers one? Where would temporary capacity protect the most revenue, and what would it need? And what does the building still have to host while this is happening?
Phase one constrains phase two. Access routes, crane positions, staging areas, and what's structurally exposed all carry forward. A sequence chosen for speed in the first year can make the third year considerably harder, and by then the alternatives are gone.
Which is why this gets decided once, early, with more riding on it than the schedule suggests.