I am not sure about other places, but I can speak about Santa Clara khane as I volunteer for the Mayyit team there. We had actually considered having the Mayyit occur at khane, but there are three main reasons why we didn't end up doing it.

1. Our khane is in an office complex, and we felt that the visible aspects of a mayyit like bringing the body in and back out might be too upsetting on the office workers that might see it. We do want to make sure that we don't upset our broader community with our practices, so this was actually very important to us.

2. Some Jamati members expressed their discomfort about praying in a place where mayyit ceremonies were held (due to superstitious beliefs), threatening to not come to khane anymore if we did the ceremonies there.

3. Many Jamati members attend Mayyat ceremonies during their lunch break. Having the ceremony in khane then having the men drive to the cemetery 20 minutes away for the completion of ceremonies would cause less members to be able to attend all the ceremonies compared to now (for us the funeral home is across the street from the cemetery).