I had a 60 day tourist visa last year , with the intention of getting the extention (which I did). The airline wouldn’t let me board. No matter who I explained it too. So I bought a cheap AirAsia ticket at the boarding gate showing my departure at day 59 - it worked and I boarded
Pretty much I buy a cheap one way ticket as a “throw away” to show I am exiting at 60 days. The airlines won’t let you board with a 60 day tourist visa and the plan for a 30 day extension.