agree on speaker output. Think that's an Irish think from its europlex days. I think the spc is a very powerful bit of kit bit dearer than the gal. Love the web i/f and spc connect. There is an output that does ee tones bit its not like horn on the gal.
this is why diallers imho shouldn't be used for alarm notification. You never know if it's gonna work when its needed as its not polled.
but as al says check you can use a conventional pstn phone
id of thought the power going off completely would cause an alarm. I'm assuming there was enough power to keep them closed. One of many reasons you shouldn't use them vs dedicated fire detection.