I applied for my passport 18th April and didn’t send my support documents in until the last few days of April. I’m due to fly next Saturday so I called on Friday 13th and I was able to upgrade and I’ve just received mine in the post (6 days after the upgrade request) which I wasn’t charged for.
Credit were it’s due the Liverpool upgrade team turned my request around really quickly.
I have a fast track appointment booked for next week which I’m now trying to cancel.