It is not enforced, true. Australian Immigration do not stamp Aus passports. When my daughter entered Thai, they asked her where is she coming from. She came from Sydney but no trace other than boarding pass.
She pulled out all her 3 passports (Japanese one had a stamp from Oct 2003 with Japanese stamp). Thai Imm officer just said "I don"t want to know of any other passports" and let her in, on her Thai passport.
Really, what did I get then with Non-O 1 year extension and a separate stamp multi-entry? Has that been merged? I came on it 29. October 2025, will leave Thai in 3 months and come back in May 2026.
Is it not? I thought that is the same. Non O visa is another stamp, on the same page in my passport. Whatever, I entered Thai October 29. 2025, with that. The only stamp was the date of entry, no comments, nothing hand written by the Imm officer.