Towards the end, he writes, "Do not put your Rancilio Silvia on a timer (to have it pre-warm before you get up in the morning). Unless you can devise a way of having it prime itself, it is not a good idea."
I have had my Silvia on a timer for many months, but I was definitely concerned about running the boiler when dry. To solve the priming problem, as part of my routine, I ensure that the last thing I do is to pull about a cup of water through the steam wand. Consider it an extended "milk flush". This should ensure that when the Silvia turns on the next morning, the boiler is already full or nearly full.