Many issues about incorrect display of ItemStack size have been raised, most of which are cuased by recursive reading of TileEntityInventoryConnector. Surely, it's pretty cool to read all adjacent containers without extra things like cables, but it's also very common among other mods that the core block of one storage network contains all ItemHandler of its parts.
Maybe you can set a blacklist to define which block will prevent recursive reading of Connector, or set a whitelist to make it work on chests only.
Additionly, DrawerController itself from StorageDrawer mod has an empty
ItemStack. So, how to display slot count when right click the Connector should also take into account.
Of course, specific-directional block like ConnectorCable can solve it, but it's just strange to leave the problem.
Anyway, it's still a functional mod with amazing and vanilla models.