Only issues I see are where you have the 500k kept and how long it’s been there (if all your usual banks are thai). Along with the source of any income if you are applying for workcation instead of soft power…
Anonymous participant certainly a more budget friendly option than me heading back to uk. Assuming your company/job isn’t based on Vietnam. So wondering if you have to get anything verified by the relevant embassy as well or were all the original documents enough on their own?