Eunometic wrote:

consequences for the German war effort.

What would have happened if the proximity fuse was not abandoned in
1940 but development continued such that it entered service in 1943?

The Allies would have need bombers to fly at higher altitudes than the
B-17 mormally did and would have required some kind of "smart bomb"
technology. Maybe bombs guided by narrow beam radio signals. Lasers
would not have been ready on time.

Bob Kolker