Tod and Robert don't live in Ayutthaya. I told you the absolute facts and requirements for the Ayutthaya office, if you are so concerned I suggest going in at 8.30AM tomorrow and asking what they require.
I used this office for several years, I assure you its a requirement, you need a copy of the Thai ID from where you are staying, along with a form filled in by them. The overstay waiver is a nonsense form they will give you there.
super chill office too, never busy unless you're unlucky and pick the day dozens of monks or students turn up at once. FYI though you need a thai to fill out a form for you and provide their ID card (guesthouse or landlord)