Many people who work in the US commute from Canada and Mexico, they should be able to use self verify to check their employment status as well. I have found that it is possible for cross border commuters who have a US credit card with a US mailing address on it to use self verify while in the US as self verify uses Equifax. Equifax operates in Canada so it wouldn't be terribly difficult to do.
On the My E-Verify Site - when you "Create Account" -after you do the self-check and receive "Work Authorized" status you should be given a message that says you are not eligible for My E-Verify or SSN Self Lock in your state at this time. Instead the site sends you back to "Create Account".
When accessing Self Check from myE-Verify the user has no button to return to myE-Verify. This may be because myE-Verify is only linking to Self Check. However, this is an unacceptable user interface and should be addressed by providing a return or cancel button on the Self Check menu when Self Check is accessed from myE-Verify.