Usually you need to give a copy of the planned schedule/appointments over the time period (better to be schedule over 6+ months), what specifically they will be doing, clinic licenses and registration & dentist’s details. Some embassies will actually take time to verify or clinic and doctors online, etc.
Anonymous participant - I would state this then, in your response. The problem is (doesn’t fully make sense), is if you extend in Thailand, you need to show that you still have the 500K, so they don’t expect that you use those funds