You realize an airplane is just an insanely complex collection of highly specialized and engineered systems? Just because they specialize in airplanes doesn't mean that the problems they have faced, solved and are still facing today are not relevant to thousands of other engineering problems.
Sure. The question remains how many of those systems and solutions are relevant to designing a fusion reactor. I think it's easy to overestimate the relevance from a helicopter point of view.
For instance, the same argument applies to a wafer stepper or 'dreadnought class' surface mining equipment. Yet it seems unlikely they are able to commercially compete on both of those extremely different specialized kinds of machines. And I wonder if a fusion reactor would be any different.
Lockheed Skunk Works, on the other hand, is not.
They've been pushing the frontiers of engineering in areas that are very much constrained by physics since 1943, and succeeding. Many times.