for every visit, if someone has a valid job and valid status, how does it matter whether it is once a month or once a week or once a year?
So why don't you tell this.. if someone has been hired by Facebook to work remotely full time and if they just have a Detroit home location in LCA/work location, what are they supposed to do if they live in Windsor? should they change the work location to SFO and fly every month there for the sake of commute?
If someone works for legitimate company, HR will know if an employee is a visa sponsored or not, what is their work location in the record etc. HRs exist for that and you are simply saying HR don't know anything just to prove your point. if someone is tagged as remote worker, they will have their home address as work location address in the HR system/workday. HR will verify based on that. if CBP asks for an employee's work location, HR cannot say something that is not present in the system. Will they pull some location out of the air and tell CBP?
People who are 100% remote will not have any other work location other than their home in the system.. such enquiries are part and parcel of HR job and it is too naive to think that HR won't have a way to pull employee's records, visa status etc. HRs can also redirect queries to attorneys if they want.. I know people who got hired remotely for Amazon, Uber etc during pandemic.. all of their work location in HR system is their home address. So HRs can definitely validate home work location if required and it is a routine thing. By your logic, what will HR say if asked about work location such remote employees? will they randomly say some office location ?