For those who have H1B employees in San Francisco, what does your lawyer say about extended work-from-home periods? A lawyer told us to amend the entire H1B, another one says if the WFH location is within 50miles it's fine to just repost the LCA.

The 50Mile guidance has been around for a long time i.e. employers don't bother unless the person is moving to a different Metro region altogether. Frankly, before they go after startups (who have no money to pay fines even if they are guilty) they will go after large out-staffing / consulting companies like Infosys, Accenture, etc.