TL;DRBe able to select a item/recipe using only keybinds when presented with the item selection popup.
What ?Be able to select the first item in the list when pressing enter, possibly only when there is only one item.
Be able to select the first 9 items in the list by pressing CTRL + Number.
Why ?You can already start searching for an item using the keyboard (CTRL + F), thus it makes sense to be able to select the item you searched for also with the keyboard. I believe it comes to many people as an instinct to press enter to select something from a list that we have filtered (with CTRL + F).
These keybinds do nothing currently in the item selection popup, so the only downside would be someone accidentally pressing enter and being confused the first time why it selected some recipe/item.