Maybe this is useful for someone, so i share my experience with ny first DTV extension in chengwattana yesterday. I have DTV under the soft power medical treatment category. I went there with an agent who knows I want to go the official route. I brought all documents. But the officer said that I needed 500k baht balance on my account for the last 30 days. I showed him a recently paid medical bill of 200k. The agent and officer agreed that they really shouldn’t expect people who can clearly afford living here to not touch the money for the category they applied and approved for. They said good you visited us now still have enough time to do a border run. He suggested to bring the same documents, especially proof of medical treatment if someone questions about the purpose of stay. Long story short: they were very friendly and don’t like their own rules but give advice on alternative solutions. I knew that the stamp isn’t guaranteed, just tried my luck. He said good thing swiss don’t need a visa for laos 😱