from sources listed by @TomD8
“A nonresident who works in another State but who performs no work in New York is not subject to New York State tax liability no matter for whose convenience or necessity he performs the work.”
Hayes v. State Tax Comm, 61 A.D.2d 62, 64 (N.Y. App. Div. 1978)
Hayes v. State Tax Comm, 61 A.D.2d 62 | Casetext Search + Citator
And the definition of NY-source income of a non-resident from NY Tax Bulletin IT-615 refers only to income from work carried out in New York.
https://www.tax.ny.gov/pubs_and_bulls/tg_bulletins/pit/ny_source_income_nonresident.htm
These cases and NY publications appear to indicate I do not have "NY-source income", because that term only applies to work done in NYS, where I have never been.
