As I said, if a film is playing then the server sleeping is not an issue. But when the film finishes and MC returns to the Theatre View, if the server is asleep and remains asleep, the Theatre View is completely unresponsive.
So, either something to keep the server awake during playback, or something to wake it at the end of the video would do the job. I imagine that keeping it awake would be the better option as the lag between returning to Theatre View and waiting for the server to wake (probably just a few seconds with a server running Windows on an SSD) would still be quite annoying.
I suppose to summarise, if any client is running then I would like the server to stay awake. I do know that starting a client from cold will cause a sleeping server to wake but starting a client from sleep will not, and that is not ideal either.
I was thinking about using a fixed schedule for the server to be on or off would be do the job (mostly) but using WOL would be the most power efficient.