Zigbee/Wink store dim levels independently of on/off. So a device can be turned of and still remember its last level. Wink supports it for ZWave devices as well although Zwave devices don’t inherently do this. Homekit also supports this concept.
The DimmerAcutator is based on Switch so the class structure in Pimatic supports this too but UI doesn’t. It would be great to have a UI widget that supports this