Inventory lags a lot (fps drops) when you open it even with the inventory opening animation toggled off, when you craft multiple items from the crafting menu and in general. The cursor for some reason teleports back to the "starting point" when you try to move fast between slots, also you can't stop the cursor in empty spaces between slots or else itt will teleport back to the main slot and this is very frustrating. The problem with the cursor is that if you try to move it a little, it's gonna try to automatically go to the nearest slot even if i wont do it, making it slow and not smooth, an easy way to solve this problem is by adding an option to disable this kind of assisted slot finding or whatever it is. Sometimes the crafting menu won't show all the categories or won't allow the player to change category on the crafting menu by pressing "lb" or "rb" forcing the player to close the inventory and open it again. Here's the clips of all the problems; since the last operator decides to ignore my feedback tagging it as "invalid" for no reason at all. 

https://1drv.ms/v/c/f5dfdba10b8e263e/EQ9SgHJMkuxCp2-gaWQtE6UB-9fPJFikrltUfqXk7V3d0w

https://1drv.ms/v/c/f5dfdba10b8e263e/EVSPAvXKZb9FigUl4u9m9fwBPWkE2yQ3OAJ_szUJZV282Q

https://1drv.ms/v/c/f5dfdba10b8e263e/ESz2wyRBSaRMhQqHL5S3dMEBPsYGa8RWOkYbzKHhnT3pcg

The first clip shows how the cursor try to choose a slot but teleports back making the inventory navigation painful, the second clip shows how opening the inventory drops fps in the last clip i show how the inventory stops working, i was pressing lb and rb the entire time but it was stuck on the search category for no reason.