Power depends on understanding - Seeing a larger scale view of what is happening as opposed to an arbitrary sequence of manipulations.
The foundations of the WW2 technologies you cite were dependent on previous theoretical efforts (ex:relativity) to develop a good understanding.
Without understanding, you get brittle demos which fail as the environment or problem description changes.
Which WW2 technologies had even a cursory dependency on Special or General Relativity?
The atomic bomb certainly had a cursory dependence on special relativity. E = mc^2, you know.
Klystrons were used in WW2, and the beam current of a klystron scales as the beam voltage to the 3/2 power (due to space charge limits). Modern klystrons operate with relativistic electron beams, but I don't know if any of the WW2 ones did.