if its anything like singapore or malaysia which has had same system running for a while. There is always travellers who havent done it and have to do there and then. Also go to back of queue while waiting for the confirmation mail. Which in Singapores case is about 5 minutes
Lots of people i find come for a couple of years and then find Thailands not for them. The advantage of starting your retirement journey with OA is you can leave your money in your home country
yes come as normal will make no difference and if anything like Singapore and Malaysia there are always people that forget and get assisted filling in. No idea when they will announce they are not very good at that.