I am on a non-immigrant (TN) status in the USA right now, and the NEXUS officer I spoke with when I updated my info (he was a CBP officer, not CBSA) advised that I keep filling out the Visitor section on the US customs card. Which I took as I'm still a resident in Canada for their purposes. So I fill out the Canadian resident portion of the CBSA Customs Declaration.

I wonder how I should fill in the application when I try to renew NEXUS...