There are two ways of getting the right address for the warehouse. Searching by Quantity or searching by ID, either way works.
I'll describe how I've done testing, and maybe you can find the adresses on your own (I don't know if they need pointers, in the vita version, only the stats needed pointers)
I'm using Edizon SE for this:
1 - Put a digistalk in the 1st slot at the warehouse
2 - Open Edizon SE, Toggle Hex Mode (press R) and search for the value "86D4E788"
3 - Get back in the game, withdraw digistalk and put a meat on the 1st slot
4 - Repeat step 2, but search for the value "87D4E963"
5- Keep repeating this process until you nail down a feel candidates.
6- bookmark these addresses
Now here comes the catch, the code follows a certain logic to build the warehouse inventory.
Once you have your candidates, go one by one searching the memory itself (Press RS on the bookmarked address), you will enter the screen below.
(I'll use Gunfort's screenshot to make it easy)
The right address will have this similar structure as the highlitghted address block (first from left to right, two "green address blocks" above it)
The Highlighted address is the one you can modify to get items, the address block to the right of it is the quantity of that item.
If the slot is empty, the value will be "FFFFFFFF".
With the first slot address found, you don't need to search for others, since the code follows a certain logic.
Just go up a few blocks until you see a similar structure as mentioned (first from left to right, two "green address blocks" above it), you will be in the right track if the slot is empty and the value is "FFFFFFFF"
Now, you can calculate or manually bookmark and edit your values, just remember that the warehouse have 100 slots so doing it manually will be a pain.
I believe the same can be done with the materials, but you'll have to search by quantity tho.
I did not made these, they were made by Nightwinter/Vaass95
If you understand logic, you can try to understand the psvita code and replicate it (it's a loop code, look up for the vitacheat doc for more info.)