Think about it. It would be incredibly glitchy. You would click upgrade and it would be like "oh ya fyi u just got raided so no more upgrading" or you said you wouldn't know until you came back online, so if you stayed online then went to raid but were attacked then you would break a shield without knowing. This game rewards money and time. If you want to stare at your screen for 6 hrs to protect yourself, it will let you.

