Some current, important things to me:
• Clarification on Build system docs would be nice, as another user stated.
• Some info on low-level networking. As said before, UE4 is room-based. An overview of sorts on the best way to delegate, or override the network driver to allow default client-side functionality to be sent off to custom servers. Same sort of info on spinning a custom UE4-based server from a low-level standpoint.
• There seems to be confusion regarding which classes are run in a client environment, and which are run in a server environment. An overview of the separation between the two would be helpful.
• An overview of the architecture behind the scenes in both the Editor and Standalone game. I’d love to know the relationship my game module has with the engine. I’ve been porting a mod system I’ve been working on to UE4 and it’s been a long trial-and-error process for getting the plugin system injected at the right point when the Engine is starting up, without killing the editor and allowing PIE to work fine. It works for me right now, but because there are some issues that don’t coincide with the docs right now, I’d like to know my options.