there's a time factor too, this involves sitting in a bus/boat for what, 2 days? If someone actually has acceptable paperwork sitting around I can see the advantage of just extending in country. Would be interested what is required.
they say yes, they call it an "online seminar" you can attend either in person in Bangkok or stream online:
"Our process is simple and convenient, as we also stream our meetings on Google Meet/Zoom/Microsoft Teams, so you can participate from everywhere in Thailand!"
Also I don't think anyone checks it once you have the visa.
You will pay tax on what you declare on the customs form. Should be only 7% VAT as computers are duty exempt. Couriers charge 200B handling fee. There isn't really any way around this if you ship it.
you get a letter from your school stating your course has ended and go to immigration in country who cancel your extension. I believe there are then three options:
(1) your letter was post-dated, in which case the cancellation is in the future and you leave by that date
(2) your letter was not post-dated, in which case your cancellation is immediate and you have to leave same day
(3) same as (2) but you pay immigration 1,900B for a denial of extension which gives you 7 days to leave Thailand.
Anonymous participant he means stay at home (or wherever you apply for the visa) for a few days. Wait a few days at step 1 before you come to Thailand in the first place.