This isn't a question, I'm just hoping this info may be of help to others
I called DWP to ask for more time to send the How Does Your Disability Affect You form, and was given an extra 14 days.They didn't give me a hard time or ask questions.
I also asked how soon I need to get a GP's letter to ensure that the letter would be considered at the same time as the form. But they would not give me any sort of deadline or any info about the time it will take to decide whether I need the face to face assessment.