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.