I'm guessing few people in this forum have any actual experience with this, however, let me just throw this out there: If you purchased a device and had it shipped to a U.S. address, and then later needed to return it and gave the same USA address (or even a different one) to receive the RMA, and took it back across the border and shipped it back from the USA (and could receive the replacement there) then as far as Obihai is concerned they'd be dealing with a USA customer, and I don't see what the problem would be. The only way you MIGHT have a problem is if you bought it in the USA, took it to Canada (or some other country), and then wanted to return it from there and receive a replacement here. I don't think the simple act of taking the Obihai adapter outside the country would void the warranty (part of the reason to purchase an Obi device is that it's so small you can take it with you when you travel) but what might matter is where you would need the replacement shipped.
Keep in mind that I'm not an employee of Obihai, so I have no idea what their actual policy might be, but I did live within a few thousand feet of the Canadian border for several years (a long time ago) and knew a few Canadians that had post office boxes in Michigan, just so they could receive merchandise from U.S. sellers that either had no idea how to ship to Canada, or wanted an excessive shipping rate to do so. That was before such things as "UPS stores" and private mail drops existed, and it made a P.O. box a rather difficult thing to get in our community because there was always a waiting list. Anyway, as far as the people they dealt with were concerned, they had a Michigan address, and that was the end of it.
