OK here's a photo looking southwestwards into the junction from Spears Road. https://www.instagram.com/p/C2swhjQInn3/
I think you *are* allow to drive "straight" across the staggered junction. No clear signs disallowing it.
I have modified the turn restriction, to use a short way as the "via" element, which might be enough to allow this, but I'm not sure.