I have a VR system where user can upload eg background image spheres on the web and view the images with Oculus glasses. I have implemented the Oculus app in Unity.
The oculus app downloads the images and creates textures with those image, at runtime.
Question:
The user can upload custom sized images. And it magically works. But would it be better to scale the images the user uploads before sending them to the glasses? What happens in Unity otherwise? Does it perform some in memory scaling?
It may do padding, but not scaling. I don’t think you should worry about it.
Thanks. But I do worry until I know for sure 
You’re going to worry a lot then. Some things are simply undocumented.