Automatic sleep mode doesn't seem to work on the Sonoff NSPanel. Here's how to fake it with a timer and some Nextion Editor hackery. Links below:
00:00 Introduction 00:57 3D Printed Stands 02:53 The Problem 03:37 Setting Things Up 07:38 Adding the Timer 09:00 Wake Button Hackery 13:40 Keeping it Awake 15:14 Saving and Restoring Brightness 17:24 Testing it Out 18:04 Almost Perfect 19:04 The Final Test 20:20 Outro