I finally get to ask a dumb question, too: I am on a 30 days visa exemption with my german passport. Can I extend that at all and can I extend that at promenada office in Chiang mai? Many thanks, guys!
TLDR : Answer Summary
If you are on a 30-day visa exemption with a German passport, you can apply for a 30-day extension at the Thai immigration office located in Promenada, Chiang Mai. The extension will cost you 1900 baht.