I can’t say why it shows a black screen after packaging. To be honest I haven’t needed to package yet since 4.4 so I don’t know if there has been a regression. It certainly worked for me before with no issues.
In terms of memory bandwidth, I meant that there is a noticeable slowdown for my application when I start uploading textures versus when I don’t. The CPU is barely being used so my guess is I’m saturating the system and GPU memory buses. There are no performance issues with smaller textures, but doing many large ones at the same time has a large cost. If I could use them directly then that portion goes away.
I also tested with my own mini-engine and getting rid of the copies and using just the original textures give smooth performance, introducing the copies starts causing big slowdowns and much stuttering.
Therefore, being able to create textures directly in the Engine with our own parameters/flags not purely the default ones or sharing our native textures with the engine seems to be a performance requirement for my needs. Support for D3D and OpenGL would be essential for cross-platform use.