I've also discovered that when ships are moving this fast, gravity turrets are of limited effectiveness; the ships seem to move so quickly that they jump most or all of the way through the grav field before the game can register its effect on them. Slowing the game down to -10 and pausing frequently seems to help some.
Some Lead ships are immune to gravity effects - Spirecraft and Golems, for example. If the Lead craft of an Exowave is immune, the followers will also be immune until the Lead ship is destroyed - then they revert to normal behavior.
I don't remember ever seeing Exowaves ignoring gravity effects otherwise.
Thanks; that's a plausible explanation. I'll watch for it more closely when the next wave comes in.
