I paid the £5 for secure return of documents but I’m still waiting for the new passports to arrive. Hoping everything will be here next week. Will update when I get it. 2 weeks sounds a bit slow but hard to say with COVID.
Still waiting for my documents to be returned but got a reply from HMPO:
In response to the latest corona virus measures relating to social distancing and necessary travel, HM Passport Office has reduced its staffing levels to ensure that these measures are followed.
As a result of this, HMPO is currently focused on getting new applications on to the system and have de-prioritised the return of supporting documents. However, HMPO is aiming to have any outstanding supporting documents returned in the next 2/3 weeks