SMS only transits the telco infrastructure, it doesn't need servers in the client-servers sense, RCS does. Not only that but RCS needs them because it includes hosting for things like images and videos that are sent in messages.
I don't think Google will allow anybody to partake in "their" RCS, the least of all custom ROMS. They will make it another thing like SafetyNet, designed to maintain their own control.
SMS only transits the telco infrastructure, it doesn't need servers in the client-servers sense, RCS does. Not only that but RCS needs them because it includes hosting for things like images and videos that are sent in messages.
I don't think Google will allow anybody to partake in "their" RCS, the least of all custom ROMS. They will make it another thing like SafetyNet, designed to maintain their own control.