I strongly recomend not to use EPS. I've been using it on a couple of my boards and they didn't last 10 sessions.
1. I used it on top of 5 mm plyboard. While the board was bending the EPS on top of the board was compressing so much, that the material didn't take it anymore (got tired) and the top glass-epoxy laminate cracked.
2. I replaced this EPS layer with poplar plyboard, but I used EPS on the edge of this layer 10X15mm, and on the edge of the 2. bottom plyboard layer, so I could easily sand the edge as seen on the pic. And guess what! The board delaminated in the middle, where there was less material to bond to, under 2 sessions, because EPS doesn't hold ass said before.
Making holes won't generaly improve the deal. Maybe it will hold 10 sessions, maybe not.
And making only pinholes won't help, because the epoxy won't even force the air out of the hole and you should laminate both sides at once. If not, the second one would have a bad bond, because, the epoxy holds bad to cured epoxy.
Don't get me wrong. EPS bond's OK in the area which is raw, if you sand it. But that's about 0,5 mm deep. The other part of the plate is torn away easily.
EPS is for house insulation and that's the way it should be.