as already mentioned, getting an O visa would be a much better idea if you donโt mind having to deposit 800,000 in a thai bank. You can add single or multi entry permits to it from inside Thailand. Plus you wonโt need the ludicrous medical form, police check and so on that you need applying for an O-A in your country
Same experience and I go back a day before you. Our officer said just get a cue ticket and seemed unconcerned that it would take very long.
I used the online appointment too but didnโt bother getting the normal cue ticket there as we showed the emailed appointment to the person letting people into the L area. Our officer at the end as we were finishing then wanted a photocopy of the appointment (my email)! That was the only hickup ๐