In the UK version of Smart things it looks like there is no generic Zwave smoke detector driver. The First Alert Smoke detector is US only at the moment and operates at US Zwave frequencies. I tried a UK frequency Zwave smoke detector from POPP but the Smart things hub only recognises the Siren and NOT the Detector.
Its a similar thing with Zwave switches, a single generic switch is recognised but with a duel channel switch only the first channel is recognised
It looks to me that the generic drivers at the moment are very limited and I do not know when (if) they will be extended
Further to this there is a significant issue with presence Fobs with the V2 version using batteries out in short weeks.
I think this is a great concept, but it still needs a bit of work, hopefully the bugs and extensions for the UK market and generic device support will be more comprehensive over time