God this is a tedious and irrelevant discussion topic. You're conflating "radar visibility" and "target lock" - two totally different things. An object executing any sufficiently dramatic acceleration at any moment, instantly breaks any target lock with all modern target lock systems, because they're designed to following inertial trajectories, not non-inertial trajectories. You can see such objects on the radar screen, but you can't "tag" them or maintain a lock on them when they zig-zag. Listen to the interviews with Kevin Day and Cmdr. Fravor - they talked about this. There are way easier ways to defeat radar, some of which many of our stealth craft already use. Try explaining that to Kevin Day, the professional Navy radar operator for the Nimitz CSG, which used the most advanced radar and target locking systems on the planet. He tried to tag the objects on his radar screen and couldn't, because they moved too erratically for the target lock to hold.