I have no experience on the subject, so this is going to be mere speculation on my part. I imagine the genus that would be most worrisome to plywood tank owners is Panaque, due to their virtually exclusive xylophagous diet. This is where the speculation comes in; I would imagine that if you use a thick enough layer of the aforementioned ACR epoxy, it would remove any texture that could be perceived as wood by the pleco.
I am very familiar with the "chewing" tendencies of Panaque and various other plecos, and am of the opinion that a large trigger is mouth feel. If the pleco feels something that it instinctively believes to be wood, it is going to start rasping. This is not to say that a pleco wouldn't go to town on your epoxy out of boredom every now and then, but I think the risk of damage to the wood itself would be minimal if a thick enough layer was applied to begin with.
Just my $0.02 for what its worth.