Assuming all goes well, I suggest making only the shortest possible stop at the Waddington control... (a) Because of the usual queue, (b) It is a bit early to be having a long stop (c) Doing the Waddington Fell climb on cold legs and having recently eaten isn't pleasant!
My suggestion is to press on and stop at the cafe in Slaidburn instead? We'd still have to climb immediately after the cafe stop, but that climb is quite a bit easier than Waddington Fell.
There is no stop at Coldwell this time. Instead, we are supposed to get receipts from
Morrisons in Nelson. I might just buy a Mars Bar or a can of Coke.