I think the issue is that signal saver is for when a storm rolls through and cuts out the signal, you would still have access to the DIRECTV service for a short period of time.
When the signal goes out, I believe the signal saver function uses the last channel tuned to as a reference to start streaming programming.
If you reboot the box, or change the channel, it has no way to know what the last channel was on or if the signal was truly lost, which is a trigger to start signal saver.
If you could just reboot the box, and it started to work off streaming immediately then in theory you could not even bother to hook the Dish up at all. You could take the Genie camping and just connect it to a hot spot, which is not what DIRECTV wants since people would not know they had an issue with their Dish setup if signal saver kicked in every time.
For the heck of it I tested my box a few minutes ago by disconnecting the satellite feed. If I have live TV and disconnect the satellite feed it works fine. If I try to change the channel, it goes to a black screen or a swm error message.
I didn't bother rebooting, I absolutely hate the reboot process on any satellite receiver. I didn't want to reboot for several minutes. The wife was already irritated I disrupted her show to test signal saver.