Not sure if this is common knowledge,but i dont think so. We can resize our inventory and its pretty simple
Open your pokemmo folder -> data -> themes -> default -> ui
and open the file named Inventory.xml with notepad or something similar
on line 28 and 29 it says:
<param name="minWidth"><int>430</int></param>
<param name="minHeight"><int>278</int></param>
you can change the