how often do you ride the board? what is the water conditions? how much do you weigh? are all the questions they should be asking.
We built a board for a team rider and it has lasted 4 years and now is just starting to get soft. and he does 20' strapless airs on it.
Eps will sooner or later start breaking down under load.. weight and you can at some to your weight with getting pulled through the water ( aka natural load)
This is one problem with eps... everyone wants light boards. well some companies use 1lb eps you can dent ( a lot of SUP are made of it) and you can pretty much dent it real easy. Most
kite brands use 2lbs eps which is a standard , but now they are still trying to keep it as light as 1lb eps board. The do a great lay up but leave out stringers ( corecell or wood or even carbon) to keep the weight down
which your board is NO stringers. the core cell that is in there looks like it is just around the screw inserts to keep the water from getting into the eps.
The next thing is eps is open cell and has air in it. With air comes expanding if left in the sun on the beach. If you think about it a hot board tossed into cold water what is happening to the foam and glass? The easiest way I tell people is take a zip lock back and zip it shut , toss it on the drive way for a hour or two and see what happens. it will expand and there with be water droplets inside of the bag. While this is happening to you boards to. It is my feeling all eps core boards should of a vent plug in them... ( which I haven't seen a lot of it until the last couple of years) SS had one in there hollow carbon board 4-5 years ago.
And yes there is a science to it to get a board to last. But you can have light and strong they just don't work together.
Just my two cents
terrie
www.jellyfishboards.com