When i first did ths problem last week, I did it from standing. A very worthwhile and obvious problem.
However, it is the lower start that is the true line and more difficult challenge. Yesterday, I went for a lamping session to give it a go (not really expecting much as I couldn't even touch the stand up at the start of the session). To my surprise I pulled the low start out of the bag on the last go of the evening, splitting 2 tips on that ascent.
Low start beta: Start on two obvious low undercuts/sidepulls and throw a heel out right to a ledge. Gain the poor crimpy rail and try to take a very difficult swing. Some nifty foot work to get the toe hook round the corner brings you to the stand up problem.
I don't want to big it up too much...but...I'd dare to say it's as good a line a Zoo York and certainly at least a level harder. I reckon 8a+ is fair but regardless of grade, this is one of the best problems I've climbed in Yorkshire.