Cannot remember how intimate you are with .svg,
Not at all intimate I'm afraid 
But I'm quite intimate with Photoshop, and I know for a fact that scaled down images will produce crappy outputs.
Okay...
We have talked about this before.
A 1024 px image at maximum jpg-quality will not produce an acceptable sky image, whereas the same image at 6000 px, compressed so much that it's weighing the same (both weighing 150 kb), will produce a far better ( almost a tolerable) sky rendering.
Examples:
Sky image 1024 px - Filesize = 150 kb:
Same image 5700 px - Filesize = 155 kb:
Size matters (resolution – not filesize), not only for the sky, but for ALL textures, and the higher the resolution – the more compression can be applied – ergo: The filesize is less important than the resolution.
I prefer sky images @ 15000 x 3700 px, and they normally weigh between 800 kb and 2.1 Mb.
Sky6000.sh3d
TestHorizon_1024.jpg
TestHorizon_6000.jpg
The larger sky image takes four seconds longer to render.
Cec
