Now that I think about it,altho the POCO field tech said emt was ok with them for the second riser, I seem to recall something in the NEC about threaded connections being required on the service side.
From what you describe the issue I brought up does not apply. A rental unit with the owner living in the main house means access is not a problem to the serviece disconnect.
Put both services on the rental and a feeder to the main house.
