he is getting "the right visa". There is nothing wrong with coming in and out of the country. I don't want to live there. I do want to go there a lot. We did much the same thing. Several extensions jumped thru all the hoops to get a retirement visa and left right before it ended. It would be nice if we could go back and forth but we can't because of the 2 land border rule
It sounds like you are getting the proper visa they want you to have. I don't know why they make it so hard. It's like they don't want people to come to Thailand
You are better off telling them you can't buy the ticket online. Just say you plan to leave on the bus or train and you plan to buy the ticket when you leave