Where you can't see the red paint, the voids were small enough that the plywood covered it.

Void Fill Elbows in the Guest Room Curve

Void Fill Elbows in the Guest Room side of the partition wall

Void Fill Elbows in the stairwell side of the interior stairwell wall

The top of a void fill elbow on the stairwell side of the partition wall

Void filling at the beam across the starwell end