Please for the love of all things holy, NEVER EVER EVER PUT MORE THAN 10 PAGES OF STUFF IN P-CHESTS. During the server reset SOMEONE ELSE'S STUFF WILL GET NUKED. Not yours. That would be far too easy. No, instead some good little billygoat who did not offend the Mighty Database by storing too much stuff in their chest will get their stuff wiped out.Then did he raise on high the Persistent Chest, saying, "Bless this, O Database, that with it thou mayst store thine loot persistently, in thy chest." And the people did rejoice and did feast upon the lambs and toads and tree-sloths and fruit-bats and orangutans and breakfast cereals ... Now did the Lord say, "First thou placest items into the Holy Chest. Then thou must count to ten. Ten shall be the number of the counting and the number of the counting shall be ten. Thou mayest also count to nine or any lesser number. Eleven shalt thou not count. Twelve is right out. Once the number ten, being the number of the counting, be reached, then closeth thou the Holy Persistent Chest in the direction downward, which, being full in my sight, shall retain no further loot."
I find this issue particularly vexing and have investigated potential solutions. None of them are good. We can limit the total number of items in a chest. That's no fun though, because you'd have to pick some arbitrarily small number of items because things are different sizes (and it would affect saving stuff for crafting). We could increase stackability of things to mitigate, but that would require an update to the hak files (which will happen eventually). We may be able to implement some insane other chest system, but that would require some heavy lifting by someone who wants to do that and understands how to set up a MySQL server at the least, and possibly linux and docker and other magical server-related tech stuff.
And on the other end of the spectrum lies to horror of the system used by Arelith, which limits you to something like 20 items TOTAL in a character's p-storage. They limit their system because p-storage causes lag and they have a lot of players. So there's an advantage to fewer players!
The good news! Beamdog is apparently working on a fix to the standard NWN database (which we use). But that will probably take until the end of the year.
What this means is that the most reasonable course of action is we try to muddle on as we do for the next few months until the fix rolls out *crossing fingers*. The best solution I have is to drop more p-chests into the mod as needed if you find yourself in need of over 10 pages of storage.
In fact, I prefer to keep chests at 9 pages or lower.