I'm facing a similar situation. I contacted the embassy to ask if a DTV visa holder can apply for a Schengen visa in Bangkok. Their response was that it depends on the applicant's "habitual residence" and whether they can prove Thailand is their primary residence, not just a temporary tourist destination. They didn't give a definitive yes or no, but said I could apply if I believe I meet the requirements.
In September, while waiting there, I saw the woman there asking two applicants about the money they had in their accounts for just one month. I believe the money should remain in the account for as long as possible.