I'll let Ex answer your question, as there are few people in the world more qualified to answer it.
I'll just say that one thing they both have in common is the need to be able to generate great power in a very aero position. Shovel uses 'crit bars' to make holding that position easier when he goes off on his breaks. Ex has posted photos which show just how close his crit positioning is to his TT positioning. As I've gotten stronger on my TT bike, I've found myself ending up much further forward on my saddle when on the road bike in crits, and I now have my saddle as far forward as it can go on both bikes. I believed strongly that doing the TT thing would help me when on the road bike, and it already has. I expect that to continue. Aero factors matter so much it's mind-boggling.