SobGroup_SpawnNewShipInSobGroup() to spawn a ship in a volume at the map origin. Then I tried to move and transform the ship using
SobGroup_SetTransform(). If the move distance was less ~900 units away from the center volume, the latter two functions had no effect. If I moved the ship more than ~900 units away, then everything worked okay.
The solution I chose was to put the spawn volume outside the map boundaries.