I didn't know that Colin! It's as interesting and as ambiguous as the Tesla story. It's been said [on here] that his [available] theoretical papers are somewhat impenetrable and certainly some are presented with more mysticism than engineering. On the other hand, though, I suspect that anyone who was able to analyse and comment on them with professional authority wouldn't be making a great career move.
As for the Blumlein story, what might he have achieved living longer and how beneficial would his demise have been to the [then] enemy? I try not to jump to hasty conclusions, as I've implied but the hiatus described might well have been very useful to anyone seeking to in suppress the truth. Indeed, I thought immediately of Mr Punch ie... "That's The Way To Do It"
Dave W