First of all, great backpack mod for early game. good job thanks for the mod. Im just some casual mc player so please dont critisize please.
Just started using packed up backpacks and it seems its hard to differentiate them if you have multiple backpacks. I get that you can renaame them but if you have like 20 or so of them its hard to keep track. 

Would like to have a visual differences on the backpacks. By either adding some colored version of the backpacks. but thats probably alot of work. Or by adding preview of the contents of the backpack when hovering on it.  Or attached an item icon or colored square or circle or any shape on the item icon?xD