If you really wanted to get fancy, tie your water knot with the amsteel loop in it... Not easily removable, but it would avoid the larkshead.
Probably won't make much of a difference, though.
Saying that I don't know what the minimum length of a WS is so I don't know how often I'd put myself in that situation. My hammock is pretty long at 3.8 m too. Might have to start taking a stepladder into the bush with me (I'm a shortarse) to get good placement of my straps.