There was previously a known issue on earlier 14.2X firmware builds where devices would reboot when S2S/AutoVPN was enabled. This is what was very likely happening to the people who posted in the thread you linked to (myself included). Even though the devices are logging power events, S2S was the real issue previously. While I am no longer seeing reboots on 14.25 with S2S tunnels, these did not immediately stop after upgrading to 14.25 which leads me to believe the root issue has not yet been corrected. Have you considered trying to 15.X firmware? It has been in development long enough now that it's probably relatively stable, but if you go this route I would ask for the known issues on the current build to be sure none of them directly impact you.
... View more