Wunderwaffen - When should a nation invest?

[RaptorCommander]

I know a few discussions have happened on this topic but I wanted to see what people thought about WHEN it would make sense for a nation to "invest" in wunderwaffen within the context of HOI4 inevitable future Wunderwaffen DLC.

If we take the historical war situation I see that Wunderwaffen should be invested in by:

• USA light investment 1939 to 1942.
• Soviet heavy investment 1941 to 1942
• Germany heavy investment 1943 to 1945.
• Japan investment 1943 to 1945.
• Finland heavy investment during winter war
• UK from fall of France to USA entering war.

Why? I see that overall a nation should be looking to wunderwaffen if:

• Your willing to sacrifice normal tech research.
• A nation has extensive combat experience.
• Your nation is getting into a desperate situation.

Why would you invest? I think that the main thing that wunderwaffen should bring to the game is a chance to turn around a war (At least hold on a bit longer). Now the precise way this is done and what actually counts as wunderwaffen or not can be left to a different thread.

What do people think about:
1. That the main game value wunderwaffen can bring is turning around a losing desperate war.
2. The nations and times i suggested for when nations should naturally invest in wunderwaffen.