It isn't typical for flow issues to show up as parts not having as much hold far away from the air intake. Especially in a static system, which yours should be, certainly for acrylic.
A gage near the pump is the best location for it, yes.
We want to see what the pressure is when:
1) all valves are closed (max the pump pulls)
2) all valves are open and table is completely covered with a non porous sheet like acrylic
3) all valves open, table uncovered, but all holes plugged (the difference between 2 and 3 is how much your channel gasketing is leaking)
With those 3 pieces of info, we can figure out what to look at next