The AIS message sent is a specific SART alert, which many navigation programs, AIS systems and chart plotters handle with alarms and other features (routing, special icons, etc).
On our boat, the VHF, Furuno CP, Vesper AIS, Coastal Explorer and OpenCPN all handle AIS-SART and AIS-MOB with alarms, etc.
I imagine others do also.
On the other hand, when on passage, just set the CPA alarms relatively close to the boat and they will go off in a MOB regardless.
Mark