Interesting. Yeah, I last accompanied someone to apply for a Thai visa in Phnom Penh back in 2016 and last applied there myself some years before that. I remember it was always around 4-5 days, but that meant that if you applied on Monday, you could expect your visa no later than Friday (not the following Monday).
It was never an embassy with a short processing time.
Sorry, I was referring to the 1 year visas you get outside the country. If you're on an annual extension of stay (either non-O or non-B) travel outside the country isn't required.
Strange, because back in 2016, Phnom Penh had a 4 day processing period (which could sometimes be reduced down to around 3 days if using an agent). I didn't know they ever had a 2 day processing time.