Ok- sorry to spam information but I figure it is probably useful to a few people in the same position.
I called Royal Mail and they said the gps location of where the signature was accepted was roughly 1.5 Miles away from the passport office. (Wtf haha)
They said I could get a full refund of the application if I need to start again as they lost it.
So have now reported it as lost, and if it turns up at HH then no worries they’ll continue as normal, but for now they’re updating my application to the replacement of a lost passport. Will update