I have a couple of SIMs with WiFi calling and IDD rates cheap enough that I decide it’s not worth dealing with other apps.

They might think they’re “anonymizing” it by altering facts.

nor is there any working holiday agreement with them.

There actually is, but only if your passport is issued from Hong Kong (they’re technically Chinese citizens).

Not a tax preparer, this is not formal tax advice, yada yada yada.

Am I correct in understanding that you’re treated as a resident in Canada for tax purposes if this ends up being 6 months + 1 week?

There’s a Canada-US tax treaty that makes it a bit more complicated than that. The “residency” section of the treaty says:

He shall be deemed to be a resident of the Contracting State in which he has a permanent home available to him; if he has a permanent home available to him in both States or in neither State, he shall be deemed to be a resident of the Contracting State with which his personal and economic relations are closer (centre of vital interests);

So if you don’t have a “permanent home” in either the US or Canada, then you’d be a citizen of wherever your social (presumably friends, family, and/or other people you’re obliged to help out day to day) and economic (employer, banking) connections are closer. By this test alone, you should be a US citizen, in which case the next step is to determine which states would tax you.

Baltic states

Funnily enough, the two times I’ve been to Estonia as a Chinese American, I’ve never been asked like that. Everyone who’s asked has pretty much accepted the response of “I’m American”.

I mean, when you yourself go as absolute as to say

super American, the rest of the world DOES NOT think like this

While just sentences earlier said

and commonwealth countries like Australia and Canada

Which are, in fact, part of “the rest of the world” aside from America, the irony is palpable.

And that’s aside from countries like Brazil, which is just as multiethnic despite not being “commonwealth”.