Very interesting.
Unmentioned in the article is the sabotage sinking of the SF HYDRO ferry on Lake Tinn to prevent transport of remaining stocks of heavy water and equipment to Germany.
https://en.m.wikipedia.org/wiki/Norwegian_heavy_water_sabotage
Bombing into a narrow valley is very difficult.
Our biggest asset in WWII was that Hitler was the leader of the Third Reich. If he'd not thought that another world war was a good idea, and concentrated on economic and technological development was much more important, he might have achieved his overall goal without firing a shot.