If I leave Thailand two days after the visa amnesty expires, will I incur an overstay penalty from the last stamp date or the amnesty expiration date?

The current visa amnesty in Thailand runs until September 26th, and any overstay fines from March 26th to September 26th are waived. If you leave on September 28th, which is two days after the amnesty ends, you will incur an overstay penalty starting from September 26th, which would amount to a 2-day overstay fine of 1000 baht.