Thanks for the survey. Well, the simple rule is to map what is on the ground. So sometimes people are eager to denote something as construction, while still nothing is happening there. Then it is back to 'grass' or something. So, I import new buildings when the first shovel hits the ground, regardless whether 'BAG'  still shows as planned. Because of the above rule. So when too early / too many houses have been imported here, feel free to either remove or to add proposed:

proposed:building = construction

That is what I normally do, when also I overshot while importing and in reality the buildings haven't started yet.
Thanks!