it works more often with Bangkok Bank, even then not guaranteed but most times. If it doesn't come through as international, you can go get the "Confirmation Letter of International Fund Transfer" from the bank it came through, although this is a hassle.
in the unlikely event the extension requirements are easily met, it saves money and more importantly time to get it in country, particularly if you are far from a border/airport. A lot of DTV holders are busy working and it can be a hassle to have to schedule a border run around work.
If they'll take bank statement showing money in a foreign account and whatever other documents like showing proof you are working/have income, many people would be able to show that and if that's it, why not extend in-country for 1,900B.
I could see it being more complicated to the point it does make sense to just bounce but it's at least possible that immigration will only need holders to show stuff they have anyway or can get easily. Will be interested to see when someone actually tries to do an extension how they get on.
Bouncing is always a backup option in case immigration do want something you can't easily provide but I can see the appeal of not *having* to leave at the six month mark.
would be interested if immigration in country will take money in a foreign bank account which only has to be there immediately before applying. This would match the original requirements and would be easy enough for many but most other extensions they want it in a Thai account and there for a period before.
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.