For these issues, please to enable debug syslog on the device web UI under Maintenance->System Diagnosis->Syslog and when the issue happens note the time on the device and download the one click debug package under the “Debug” tab. We would need to review the debug files to further understand the issue. You can open support ticket for these issues.
For your reboot feature request it is just a workaround. If you are using asterisk system such as UCM, there is function under Zero config to reboot the device. You can also use asterisk cli to send NOTIFY to device with check-sync to reboot.