Are you suggesting for the US or the UK?
The remotec ZXT 120 does work with smart things as a basic Z wave thermostat, a number of community members have it. It’s not on the official device list but you can find the code in the forums.
The fibaro smoke sensor has problems with many zwave controllers. Not specific to smartthings. It is a certified zwave device, but really only seems to work well with its own controller because of the way they’ve implemented the tamper alerts. Read reviews on the vendor sites. I wouldn’t expect to see this one anytime soon, although other fibaro devices are supported.
The Aeon labs range extender works fine with smartthings. It pairs as a switch. It’s unlikely that you’ll need it though, single-purpose range extenders were mostly used through version three of zwave. We’re now at version five. At this point any dual purpose repeater device, typically a plug-in module in the UK or a light switch in the US, will give you the same range extending capability but you can also use the device for its other purpose. See discussion topics in the forum for more details.
The radiator thermostats would be cool, there are a couple of members looking into those. I don’t know if anyone has them working yet, I don’t think so.