It's a nice feature, but it's almost unusable for a several reasons.
It require huge amount of time, which is probably realistic, but I suppose not very gameplay friendly. Even dedicated cleaner can't reliably clean any significant area.
It has higher or at least the same priority as normal cleaning, while normal cleaning is way more important.
So no one would designte cleaning area, because it effectively disable all other cleaning for quite a while. It's just too high price for something so minor.
It works during the snow, which is probably fine, if aforementioned problems would be addressed.
When spring comes, the extreme cold and the snow will disappear all over the rimworld. When it's summer, your colonists will have heatstroke(aka hyperthermia). When it's autumn, the extreme heat will end all over the rimworld. When it's winter, your colonists will have hypothermia. Add/remove snow clear areas will only work in winter, but not in summer. Anyways, Thanks!
I mean, it is very realistic. Clearing snow is one of the most pointless tasks in real life, as it will be back again soon. But you do it anyway because it needs to be done.
I usually just assign critical paths to be cleared in my outdoors areas and that's about it. When you have a dedicated cleaner, it doesn't really affect their schedule much.