I think the extra lag on some spells/skills/actions is more for game balance then for realism. So the idea that plant growth lags you for x amount of time is not because the plants need this time to grow or whatever but because it provides a balancing effect, that is you lose the ability to enter commands during the lag period. By negating the lag because of a hostile action towards the player using the lagging action would remove this balancing aspect of these skills/spells etc. While it might be neat from a realism aspect if say the plants did not finish growing in your example till the commune was finished it is another aspect of balance, you are going to be lagged but at least you got of the positive effect of the commune.

Just my thoughts, oh and it would suck if request was changed like this, it would take all the risk away from requesting an item.