Out of curiosity, can I ask how old you are? It’s just that I’ve had agents tell me they can get an account for a DTV holder who is over 50, but not younger.
Your application for DTV would be based on your remote working. Nothing to do with anything else. No need to mention anything else. It’s not relevant and won’t help your application at all.
Doesn’t need to be a return to the original destination to satisfy either the airline or Thai immigration. Just needs to be onward travel out of Thailand
Is the gym you’re currently training at able to assist with DTV applications? If so, you might want to prepare paperwork from them if you intend to extend your stay rather than border bounce.
It also might be prudent to do that anyway in case you’re questioned at some point during the potential five years of your visa.
As for your 90 day report, just a TM30 at your local immigration office is enough.
Anonymous participant they might question you but I think it’s unlikely. If they do just tell them the truth. You thought the DTV wasn’t going to be approved, you got here and it was.