I just found these Tuya Devices for Smoke and CO detection (separate modules) with 10 year Battery Life under brand name Heiman - you can find them on AliExpress.
It looks like they will integrate with SmartThings Hub - Zigbee HA3.0
At least per the specs they appear to have CE mark and EN14604 which is good for the EU which says something about their capability although don’t see any US certifications
I’m in the US so probably can’t be used as a required device - however I’m thinking these could be used as auxiliary devices, which could be used to deliver Smart Alerts (and even trigger the STHM?)
i.e. to supplement the ‘dumb’ (legal) detectors as opposed to replacing them?
They are certainly attractively priced at $22 per smoke and $38 per CO on AliExpress
Any Euro users here?