yeah, you could spend 2 lives to watch all the videos

unfortunately the documentation has many missing part, but sometimes the developers appear unexpectedly in forum threads to help you out when you want to use undocumented features of the engine. (e.g. in a custom level streaming question they pasted in some code from their unfinished game called Fornite, what I need to port my game concept from 3dgs to ue4)

I'm sure unity also has an appropriate response on it... in a game dev article a developer (of Wateland2) said porting their game from unity 4.5 to 5 will allow much more users to mod the game...