I finally got to rescreening the wood chipper to use it as an EPS grinder. It looks like it will work okay. The foam pieces have to be small enough to fit in the hopper, but once introduced to the blades, the foam gets ground fine enough to do the job.
We’ll load the chipper into the back of a stable vehicle so we have a drop for mounting a collection bag. I will be making it out of sun shade cloth if I can’t find a collection bag locally that will work.