I took this route, and it works fine.
I added one of these First Alert smoke alarms to my setup (all the rest of the alarms are hardwired Kidde alarms). I then added an Insteon Smoke Bridge to my setup. It has always worked as intended during testing, and installation was easy. My ISY now sends alerts, turns on all the lights, turns on my Z-Wave Aeotech Siren, etc.
BTW, no hacking of the alarm or Smoke Bridge was necessary. The First Alert alarm uses a differently shaped connector than the Kidde alarms do, but it's easy to swap. My hardwired Kidde and First Alert alarms are compatible, as I can smoke a Kidde alarm (at the other end of the house from the First Alert), and the ISY runs my programs.