According to the
USCIS's description of an alien commuter, you are expected to commute at least twice a week to the US for work (as a standard commuter), or be in the US for less than six months for your job (as a seasonal commuter). However, there are a lot of restrictions to your PR status, like not being able to sponsor family members or use this status to count towards the residency requirement for citizenship. Also, if after your US job has ended that you can't secure further employment in the US, this status will be terminated. I think this is for current US PRs so that they won't lose their status because of the residency requirement by living outside of the US. If you're not planning to live in the US as a PR or apply for US citizenship after your job ends, I don't really see a point in getting this.
