The backpack is a great addition to Teldaria and it allows for a lot of ranks to have less imaginative perks (lol) but I think it has one glaring fault which makes it near to unusable in most situations. This is that it takes 5 seconds to open. I will go on to propose two solutions to this, but first I will explain why I see it as a problem. I think this is that it makes it very inconvenient to use in general. If I am building and I want extra space for more blocks, every single time I wanted to remove something I have to just wait motionless doing nothing for it to pop up. Even to store one item, you are wasting 10 seconds opening to store and remove the item. My solutions to this vary in their complexity to implement but also their functionality. The "best" solution I can devise would be to make it so that it has no cooldown at all, but being moved through outside means would instantly close the menu and drop all items you were holding with the mouse. This is to stop it from being used as a combat tool (which is the only reason I see it having a cooldown at all right now) while keeping quick, easy access to it. The faster and easier solution would be to simply lower the cooldown, to 2 or 3.