No disconnect, no secondary drain, they cut 2 trusses out of the way, ductwork all over the place.
The second pic shows the return side. Truss cuts down the size of the return. The supply has the plenum the full size of the cabinet. This is the fourth supply plenum I came across this week where the plenum is the size of the cabinet and not the blower opening. Don't need no stinking disconnect or truss.