Does the type of item you apply the Replicate Magic item infusion matter? I mean, if I infuse the replica of Bag of Holding in a dagger, does the dagger turn into a Bag of Holding, or it stays like a dagger with the same effects?
Whenever you finish a long rest, you can touch a nonmagical object and imbue it with one of your artificer infusions, turning it into a magic item. An infusion works on only certain kinds of objects, as specified in the infusion's description. If the item requires attunement, you can attune yourself to it the instant you infuse the item.
The Replicate Magic Item infusion states (E:RftLW, p. 63):
Using this infusion, you replicate a particular magic item. You can learn this infusion multiple times; each time you do so, choose a magic item that you can make with it, picking from the Replicable Items tables below. A table's title tells you the level you must be in the class to choose an item from the table.
If yes, can the common armour variant magic items found in Xanathar's Guide to Everything, such as Cast-Off Armor, be created? Can I use this to get a set of Half Plate Armor from this infusion?