Very good question John, I would be interested in the feedback as well. I think it has come up on AVS before, but the answers varied as wide as the "speaker break in" topic.
I know my basement HT stays relatively cool all the time anyway, and I'm not sure my fan runs much anyway after shutdown. So maybe in this situation it would not be a big deal. I know that I run my Z2 in low lamp mode, not that this matters.