Efficient ways to optimize the downloading and unloading of large textures?

Hi guys I am working on a project that downloads lots of textures, many of them for a cube map, places them , and then once the player changes their options we unload and the textures and begin loading our new set of images . I wanted to know is their a more efficient way that I can be doing this I have recently begun to encounter some memory issues on both android and iOS machines .

Here is an example of unloading one group of our images :

public void UnloadTextures(){

	Resources.UnloadAsset(leftPano);
	Resources.UnloadAsset(rightPano);
}

private void UnloadTextures(Renderer pano){

	Material[] mats = pano.materials;

	for(int i = 0; i < mats.Length; i++) {

		Texture2D tempTex = mats *.mainTexture as Texture2D;*
  •   	DestroyImmediate (tempTex,true);*
    
  •   }*
    
  •   Resources.UnloadUnusedAssets();*
    
  • }*
    Here is a second example of unloading our texture in the project :
  •   	Texture2D leftTemp = leftShutter.texture as Texture2D;*
    
  •   	Texture2D rightTemp = rightShutter.texture as Texture2D;*
    
  •   	leftImage.texture = (Texture)PortalCache.LoadImageFromCache(downloader.DownloadedImageLibrary.leftSpinPaths[index]) as Texture;*
    

leftShutter.SetNativeSize();

  •   	rightImage.texture = (Texture)PortalCache.LoadImageFromCache(downloader.DownloadedImageLibrary.rightSpinPaths[index]) as Texture;*
    

rightShutter.SetNativeSize();

  •   	Resources.UnloadAsset(leftTemp);*
    
  •   	Resources.UnloadAsset(rightTemp);*
    

Is there anything I can be doing that is more efficient in terms of unloading these textures? As I mentioned I am also downloading them from web , So perhaps there is an efficient way to manage downloading of textures from the web ?

Did you figure out anything? Even I have a similar usecase where I’m downloading huge textures. Need to know how to free up the memory efficiently