Level 22 solution

Solver-verified route

1. Place the stack from Slot 2 onto hex (0, 0).
2. Place the stack from Slot 3 onto hex (-1, 0).
3. Place the stack from Slot 1 onto hex (1, -1).
4. Place the stack from Slot 2 onto hex (0, 1).
5. Place the stack from Slot 3 onto hex (-2, 1).
6. Place the stack from Slot 3 onto hex (0, 1).
7. Place the stack from Slot 2 onto hex (-1, -1).

The solver clears this board in 7 placements. Hex coordinates are axial (q, r) from the board center.