@swan0206 : I know right.... One hell of a ride....
So nothing prevents you from applying for an amendment from outside the US. In fact it is best practice to apply for an amendment as soon as any terms of your employment have changed. Specifically, title, job responsibilities, location, salary, etc. It takes longer in normal processing outside US. I went with premium processing, and it was approved within a week.
Most IT services companies, especially contractors avoid this because they are already scrutinized and the location is based on client location.
In my case, I am full-time employee for more than 6 years with the same company, transfered to Canada and brought back to a home office location servicing multiple clients across US, so the profile was direct and clean. My organization also provides me the said salary as indicated in the LCA application and other standard employee benefits like 401k and medical insurance, which contracting companies don't.