Is the surface area of the puck(s), subjected to the plates, changing?

I.e. suppose you use one of these pucks at X psi. If you used 2 the same as before, side by side between the plates the area subjected to the plates has doubled, in which case you need to double the pressure on the guage to get the same psi at the puck. If those 2 puck's sat on top of each other then the area subjected to the press stays the same, so the guage pressure stays the same as scenario 1.

The guage pressure, only reads the pressure in the pump. If the pumps internal area is the same as the size of the puck, what the guage shows is what the puck sees. If the puck is bigger than the piston, then the effective pressure at the puck is reduced at the same guage reading, by the difference in area.

I hope that makes sense.