Watching the flight tonight, I finally realized why heat shields are so unnecessary. By firing the engine in the reentry, direction of flight, the engine exhausts pushes the reentry, friction heated gasses away from the body of the rocket. If they don't come in contact with the body of the rocket, it remains cool. As for STP-2, two of three boosters were recovered. The core trying to land on the drone ship 'came just that close.' The previous mission landed the core but rough seas toppled it. Source: Bob Wilson
One half of fairing also netted at sea. More words here: Live coverage: SpaceX’s Falcon Heavy lifts off from Kennedy Space Center – Spaceflight Now
A theory for getting flat faced objects to fly fast through the air is to use a plasma jet to act as a nose cone.
The Russians have a torpedo that fires a jet of gas in front to make a cavitation ‘field’ for a super fast torpedo. Of course target detection by ordinary means is impossible but if it is a slow target ... it gets GOT. Bob Wilson