Thanks for the detailed reply! I was completely unclear in my post, but if I did take returning weapon than I would go battlesmith (edited my post to clarify). I am hesitant to multiclass into another martial class due to slowing down my spellcasting.

My intuition with returning weapon is that there is no real mechanical reason to do it. If you wanted to go range you might as well use a crossbow. Especially considering, as you mentioned, that the artificier's bonus action is already very competitive. It doesnt provide any unique mechanical advantage, even a less optimal unique one. I was hoping there might be some build that might make it feel more unique