>"You do not need to apply for an EAD if you are a lawful permanent resident. Your Green Card (Form I-551, Permanent Resident Card) is evidence of your employment authorization. You also do not need to apply for an EAD if you have a nonimmigrant visa that authorizes you to work for a specific employer (for example, you have an H-1B, L-1B, O, or P visa)." (ibid) //

I've only done a cursory check but all the USCIS talks about residence, do they allow non-residents the right to take up employment; is that anticipated as a possibility, do people have to reside in (or have rights to reside in) USA to be a worker there?

https://www.govinfo.gov/app/details/CFR-2012-title8-vol1/CFR... is probably useful to others looking at this (AFAICT you have to "download" you can't view it online, but I'm on mobile).