This is factually incorrect. You really can threaten to throw Grave, just take a small step.
Next, this is not a bug that he can throw loop. It's an intentional part of the design, so it belongs as a balance suggestion.
Next, we will probably change the balance so that he can't throw loop midscreen.
Also, even after that is changed, the exact distance that each character flies backward will vary by their size. That detail is too hard to adjust, so it will just be what it is.