Here currently across Chiang Saen and yes you have to spend 2 nights here. It’s the casino hotel in the special economic zone highly DONT recommend coming to this border crossing to stay here. The Thai immigration officer didn’t even recommend we cross and stay overnight, although we did.
When you say copies of agency/school/etc etc, what are you referring to? Proof of our previous ED visas? Also in the same boat and planning to apply for DTV at Vientiane embassy 🙏🏼