Pillboxes I lack a lot of scenario experience with. Fortified buildings I have more with and they don't truly work. The attacker can and does just small arms fire the defender out of their positions and then advance in. No real fire and movement and no real usage of breaching or other such tactics.Better to leave them as they are as they already work well
It occurs to me later designed ASL scenarios have fewer turns - perhaps a reason is to actually push the attacker to move up and not just sit back and gun the defender to death?