Hatched filling for zones has been merged. I just compiled and it looks nice:
The screenshot is only a quick example, I won’t use it in this case, maybe I never will use it. See e.g. https://electronics.stackexchange.com/questions/5139/solid-ground-plane-vs-hatched-ground-plane for some opinions. Flexible circuit or impedance control may be good reasons to use it.
Smoothing means rounded/chamfered corners:
EDIT: the feature itself is of course incompatible with earlier versions, but if you don’t use it, the file should be compatible with earlier versions.