Laszlonagy,
this is what I do in terms of producing schedules for grouped zones, this works awesome. The point is now to show the result of summing those chosen zones on plan.
Of course I can use a text object and type in the result of summing ...Thats OK if we are dealing if lets say 5 groups of zones.
But what if its 350 zone groups with around 1500 zones ( 350 apartments with usually 4 rooms, kitchen, 2 x bathrooms, hall etc. ) ?
It's a lot and we do it in our office now by hand but this is an enormous work so we update them every few months instead of having them updated all the time if they where automated.