Ask Todd the process of converting a 30 day exemption over to a extension based on retirement. May need to convert to NonO first then convert to the extension. There are processes but need to do fast so you have the days available. You might make a visit to Laos to get a tourist or Non O visa and allow it to be converted. Don’t need to return to UK but do follow the rules.
I’m not an expert but I think you may have to start the process over. Your extension was voided if you left the country and did NOT have a re entry permit.
Generally plan an extra 30-45minutes to apply For a re entry permit. If you don’t get it you will have to return on an exemption (depending on your passport) you can NOT get Generally get a visa at the airport on arrival (depending on your passport)
Yes you can walk in and get a queue number when you arrive. If you go online prior (I think it is 24-48hrs before) then you can bypass the lines. Can save wait time.
The Visa is “able to be used” as soon as it is affixed in your passport and an O-A you have up of 1 year to enter the Kingdom. So for the first year you can come and go as you wish and every time you enter you should get a stamp allowing a full year in country. To make the most of this visa apply for it as close to travel time as possible,
also it is good to remember while folks call it a “retirement” visa it is not. It is a O visa based on “something” the regular O...which is probably your best bet will allow I believe 60 days and then you re enter right before it expires and get another 60 days and maybe extend for 30 day at immigration shortly before that last days ends. I’m not very familiar with the basic O but it is more easily obtainable.