Interview waiver for 14 year old H4

Hi - My son (H4 visa) turned 14 last month and we had already booked dropbox appointment for myself, wife and son - appointment was scheduled for June’2024. I did not see any questions related to 14-years category while scheduling dropbox appointment however came to know recently that 14-years should go for face-2-face interview.

May i know what are the options available as we had already scheduled dropbox for all 3 of us?
Can we drop the documents on the scheduled date for all 3 of us or reschedule my son’s appointment to F2F?
On submission, will there be any issues like 221g and called for F2F or visa will be denied or no issues at all?
If I need to reschedule, any help on how to schedule separately for my son? can we accompany him during F2F or will be be bio-metric alone?