Hope this helps people, here was my timeline for renewal of a child’s passport:
Passport printed 2:13pm on 16 March 2022
Application approved 12:06am on 15 March 2022
Documents received 1:22pm on 10 March 2022
Application received 10:13am on 17 February 2022
Identity details received 10:13am on 17 February 2022
Email sent to person confirming your identity 7:27pm on 16 February 2022
Ask someone to confirm your identity 1:55pm on 13 February 2022
Application submitted 1:55pm on 13 February 2022
The only thing I’d want to add is that it took a week from “Passport printed” to me actually receiving the passport.