Maybe it qualifies for Thai Visa Advice. My old passport with my ed visa is valid until summer. A new passport is ready for me at the embassy in Bangkok. Unfortunately, when I pick up the new passport, they will stamp the old passport which contains the visa invalid. Will there be any problems for me at the airport with the immigration when I want to leave a couple of days later, showing the old invalid passport and my new passport. I don't want to travel 800 km one way back to the local immigration office and the next day back to Bangkok just to fly out.
TLDR : Answer Summary
The user is concerned about potential issues they might face at the airport when leaving Thailand if they have an invalid visa in their old passport and a new passport ready from the embassy. The discussion includes the protocol for transferring visa stamps from an old passport to a new one and the uncertainties involved in showing both passports during departure.