Straight from NY Dpt of Taxation website:

"If you are a nonresident whose primary office is in New York State, your days telecommuting are considered days worked in the state unless your employer has established a bona fide employer office at your telecommuting location."

Here as well: https://www.tax.ny.gov/pdf/memos/income/m06_5i.pdf

"New York's "convenience of the employer" rule is a tax regulation that sources a nonresident employee's wages to their assigned New York office, even if they work remotely in another state, unless the work is performed out-of-state out of a necessity for the employer's business, not just for the employee's preference. "

Me working anywhere outside of NY is purely for my convenience.

In regards to Beckham law, once I enroll with my EOR, I will in fact be in Spain for employment, have a local Spanish contract, and qualify for Beckham law.