If it’s of any help to anyone this was my timeline (it took 5 weeks from application to receive everything back, inc. supporting documents):
Passport received on 01 March 2022, supporting documents received on 08 March 2022.
Passport printed and sent 1:21pm on 21 February 2022
Application approved 12:34pm on 18 February 2022
Documents received 6:46pm on 10 February 2022
Application received 8:07pm on 31 January 2022
Application submitted 8:07pm on 31 January 2022
My biggest worry was that the passport took over a week to be delivered from when it had been printed – I thought it had gone missing!