I think I have an answer to my question, or at least a solution to my concern . . .

A perforation roller may be the solution, if more resin flow through the peel ply is desired.  I am going to see if I can get  one and try it out to see if the resin flow downward into the glass fabric is better.

I have run a test of resin infusion, using VARTM.  I infused a 200mm x 450 mm (8" x 18") slab of 3 layers of 1.5 oz CSM. 
As you can see below . . .


Before doing this test piece, I tested the peel ply, using water, to see how porous it was.  Essentially, the peel ply that I have is quite fine and water did not flow through it very easily. 

Fortunately, it looks like the resin flowed through the peel ply well enough to saturate the test slab, except for the last 50-75 mm (2-3").  FWIW, the direction of resin flow was towards my hand, air being taken from the side that my hand is on and resin fed from the far side.  Therefore the amount of resin travel via the flow media was about 400-450 mm (16-18")

My question is if there are certain grades/weights of peel ply that would be more porous and let the resin pass through more readily?  If so, what should I be looking for when buying some?  I am not sure what I bought originally, but it seem like a very fine weave.

Thanks in advance for any insight on various types of peel ply.