[Retros] Double-pin mate

[afretro]

Here▓s a double-pin mate:
1.Pe2-e4   Pf7-f5   2.Qd1-g4   Pf5-f4   3.Qg4xd7   Ke8-f7   
4.Qd7xc7   Qd8-d5   5.Pd2-d4   Qd5xa2   6.Sb1-d2   Qa2-b1   
7.Ra1-a5   Sb8-d7   8.Ra5-f5   Sd7-f6   9.Pd4-d5   Ph7-h5   
10.Bf1-c4   Rh8-h6   11.Sg1-e2   Rh6-g6   12.  O-O    Qb1xc1   
13.Qc7-d7   Qc1-a1   14.Pd5-d6   
How many pins can be effective in the mate position of an SPG (regardless of the mating piece)? Three? Four? Or even more?
Best,
Andrey