There is no need to revert your changes in the region.

As a general rule, this import has the most accurate and correct building positions.

The import will merge existing buildings at the position (keep all tags, but replace geometry). So it should be fine.
- I have also seen that some (but very few) of the imported buildings are quite off, in these cases it's reasonable to draw after the imagery instead of the imported building.
- read more about the import here: osm.wiki/Import/Catalogue/Norway_Building_Import

Are there any buildings you think about in particular?
- I try to verify all imported buildings to check if they are aligned with imagery (not too far off)

Okay, Maybe it was an old fence error, and not MIGRO19's fault. Sorry