7/3/19 #2: Particle board as spoilboard ...
I think the use of MDF is because the vacuum can get through it and hold the parts down.
Particleboard might not let the vacuum through.
If you are using a pod hold down system then it probably wouldn't make much of a difference.
7/12/19 #3: Particle board as spoilboard ...
Years ago I used to use cheap particle board as spoilboard.
I had to skim both sides to get good suction. It worked and was cheap but the time and labor to do the extra skim on the bottom (inside) probably negated the cheapness.
For the last 20 years we have been using ultra lite MDF (like Trupan). Much smoother finish when freshly cleaned up. Cost is not that big of a deal if you are carefull not to gouge up your spoil.
We can keep one for months if we get lucky and no one makes a big booboo.
7/13/19 #4: Particle board as spoilboard ...
Website: http://www.sogncabinets.com
I surface both sides of a new spoilboard.
I don't know what particle board would gain you on the input side, but I can't image it would help anything in terms of vacuum or keeping parts in place.
7/15/19 #5: Particle board as spoilboard ...
Particle board will not work. MDF is the only way to go.