I want to thank this group for all the information and prompt response to all answers, I found it very helpful during my application process. Now I want to share my experience in case someone finds it useful.

DTV application (Muay Thai) Approved London embassy.

Application submitted - Monday 13th October

Requested additional document (e-ticket) - Thursday 16th October

E-Ticket submitted (only outbound flight) - Friday 17th October

Visa approved - Today 22nd October

I submitted the following documents:

Last 3 months of bank statements downloaded from the bank app but also got the current balance printed at the bank with a stamp and merged everything into one PDF. (I read in some previous posts that the stamp was requested so I got a stamp just in case).

Driving Licence as proof of current location (Also suggested in some post by successful applicants and by the gym I will be training)

Scanned copy of Passport, Photo and the documents provided by the Gym (I used FitFac Muay Thai Academy in Bangkok - Highly recommended).

Anyone here used Fitfac Muay Thai academy to get their DTV?