Skip, Digital dialer for Fire is almost obsolete but when used, NFPA & NICET required that the primary line be dedicated, the secondary you could continue on to other equipment.
I would look into, (or have your client) look into
connecting those fire alarm controls into radio transmitters. That would also free up both CO lines for whatever they want to do with them.
I know that here in IL. even group homes as you mentioned are required to have an actual fire alarm, not simply something tied into a burglar alarm or a burglar alarm type control.
If these are not "required" systems then you can usally do what ever you want.
I've also found out the hard way many years ago that regardless of State or national codes, local
jurisdiction has the final say.
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MrG