The versions you're asking about are specific internal build numbers used by developers and distribution platforms:
While early updates for the game focused on adding competitive features like The Eliminator or Super7: High Stakes , updates in the 1.465.x and 1.478.x ranges shifted focus toward maintaining internal systems. forza horizon 4 update 1465282 1478564 e full
(Steam)
If you're looking for a comprehensive or "full" update, it's possible you're referring to a cumulative update that includes all previous updates up to a certain point. However, Forza Horizon 4, like many modern games, uses a more continuous update model, with smaller patches being released regularly rather than a single "full" update package. The versions you're asking about are specific internal