If HMPO write off to the counter signatory in our case the letter was sent on the Wednesday and not received until Monday, reply straight away and sent back special delivery received on the Tuesday. Got to examiner on Wednesday (if special or signed for it goes to a different place to be recorded before going back to the examiner.
Passports printed early next morning and received the next day at 1030 am
I believe bulk of the delay is the time spent queuing to get to the examiner, once with them it's pretty speedy, even if they do have To write off to do checks.
Ours only come on Friday , when they were received on 2nd May into Durham and we travel in 13 days. So have spent hours on the phone, this thread, engaging MP and lots of sleepless nights.
I wouldn't wish this experience on anybody.
To add, our MP wasn't much help only giving callbacks from offices and was told couldn't move us up the queue until 7 days before our date of travel
Good luck to everyone x