I started thinking about this today as well as I was reviewing an RFP. The RFP references Michigan's guide lines for multi-line telephone systems: https://www.michigan.gov/documents/msp/FINAL_MLTS_Guidelines_503991_7.pdf
At first glance this it appears that to meet the requirements you need to enter the location of the phone in the "Address Line 2" box of the E911 emergency address:
According to that PDF it looks like this will be required for MLTS by December 31st 2019.
"Under Michigan law, the provision of an Emergency Response Location (ERL) for every telephone capable of dialing 911 on a multi-line telephone system is required by December 31, 2019."
I know in the past we talked about introducing locations into Monster UI to help with managing e911 for larger accounts with multiple locations.
As I was thinking about this specific use case (for RFP's requiring the location information) I was wondering if it was possible to allow the location information (Address Line 2) to be merged from the User and Device level when the call is processed. Perhaps this is what you were mentioning earlier in the thread Darren.
The wording above makes it sound like all MLTS systems will require this by 2020.