Bleeding edge technology is very new (and possibly dicey) high tech IT hardware and software of the type that Silicon Valley firms specialise in.
Bleeding - cursed (as in bleeding heck etc) advantage- edge?
Bleeding Edge is hardly obscure whether you are 20 or 80.
On the other hand, Tropic of Capricorn (an out of print novel from 1938) plus so many other clues in almost every crossword is a mystery to anyone under 60.