I intend to upscale from the beginning because it will give me a bigger canvas to work from
That doesn't make sense - you can only lose information when you upscale (unless it's a perfect integer scale that preserves every "real" line, and even then it'll be full of "fake" information).
There's also the fact that you'll be wasting bits on the final encode - bits which would be better spent to create a higher-quality SD version, which can then be upscaled on playback.
What are you using to upscale?
DE