> To go further, I believe there’s good data on cost of living, geographically.

I like the goal of making sure visa works are paid well for where they live.

I would not want to restrict the visa worker geographically though. Or alternatively I am unsure about the overhead of tracking the location visa holders and enforcing salary changes.

Might also have unintended knock on effect of encouraging job growth in low cost of living areas.

This already happens. One of the ways of qualifying for a National Interest Waiver for doctors, for example is by agreeing to work for some time in a designated underserved area.