Papers can be surprisingly complex. Which is why there are really only a handful that people use for photographic work. You need something that is heavy enough to carry the image and bound together enough to withstand the wet processes. A good example is paper money. It is made from a strong rag paper that can get washed 100s of times with no real damage. It can be mangled and abused heavily. But notepad paper of the same thickness will dissolve in water.
If you don't want to switch to a known pt/pd paper, you might want to do some testing of your own on the paper stocks you are considering. Soak them and then pretend to put them through the process using just plain water. See how much abuse they can take.