I think the only harm is the potential for under pitching
I'm not sure 1 pack in a 1L starter is going to give you the cell count you'll need (236 billion) for a 1.065 wort. On a stir plate you'd need 1.5L, without you'd need 4L.
There's a free pitching rate calculator here:
Also, with a 1L starter you don't need to (IMO) worry about cold crashing a decanting, you should be ok pitching the whole thing in there without an effect on flavor