Level 68 solution

Solver-verified route

1. Place the stack from Slot 3 onto hex (0, -2).
2. Place the stack from Slot 2 onto hex (1, 1).
3. Place the stack from Slot 3 onto hex (1, -1).
4. Place the stack from Slot 1 onto hex (1, 0).
5. Place the stack from Slot 3 onto hex (2, -1).
6. Place the stack from Slot 2 onto hex (2, -2).
7. Place the stack from Slot 1 onto hex (-1, -1).
8. Place the stack from Slot 1 onto hex (0, 0).
9. Place the stack from Slot 3 onto hex (-1, 1).
10. Place the stack from Slot 2 onto hex (0, 1).
11. Place the stack from Slot 3 onto hex (1, -2).
12. Place the stack from Slot 1 onto hex (1, -2).
13. Place the stack from Slot 2 onto hex (-2, 0).
14. Place the stack from Slot 2 onto hex (1, -1).
15. Place the stack from Slot 1 onto hex (1, -1).

The solver clears this board in 15 placements. Hex coordinates are axial (q, r) from the board center.