That's pretty impressive on the interview. Our processing times are almost identical.
UK Citizen:
Applied UK Border Force Tuesday 13th February
Approved Wednesday 14th February
Applied TTP Global Entry Tuesday 13th February
Conditional Approval Tuesday 27th February
I'm not in London so have booked an interview for April 4th when I know I'll be around. There is currently availability every working day in April.
I've also seen that as of February 24th, you can complete your enrollment on arrival at participating airports which would have been a useful option for me had there been nothing in London.
https://www.cbp.gov/travel/trusted-t...llment-arrival