AFV Leading activation questions

[Blackcloud6]

Since assault is not a move action, there is no limitation for entering an assault hex even if it is prohibited terrain (like crossing a hedge for motorized) is another example.

I think there is a prohibition since Assault "movement" is covered under the movement rules: 5.32 Assault.  The APC still moves in an assault and thus cannot cross prohibited terrain.   And that is a simple clarification anyhow and does not need a new rule nor a rule change.