The inventory can be searched with 4 bytes. Best to do this just after loading save data so the inventory addresses still in relatives.
For example:
1. Prepare a stack of 15 ship ammo in ship cargo, put the item stack you want to modify next to it
2. Save the game when you are next to ship fuel trader on father ship, then restart the app
3. After reloading the save, reattach your CE to the game app
4. Search for this ammo stack (15)
5. Buy ship ammo from the trader, the stack should be 30 now. Search for this value
6. Repeat previous step 5 until you have 1 address left, abort if you can not find the address and created a new stack because this will scatter everything.
7. Once you find the address, the other item stacks address should be close by (about +/- 4C to 50 address relative)
This works for any items that could appear in inventory such as crystal, build materials, mod box and amulet box. Be careful of the stack limit, for example crystals only have stack limit of 100, if you modified a stack to 400 then it will splits into 4 stacks after reset.