Pixelated Graphics - How do AE/Premiere/ME handle scaling when rendering?

I've been trying to find a clear answer about rendering out of After Effects and Premiere without pixelation. What seems to be happening is that certain elements in my comps/sequences are rendered at a much lower resolution than other elements. So I get a clear graphic on top of a highly pixelated one. I'm rendering everything at maximum render quality using CUDA. I tried purging the cache.

What I imagine is happening is that because my original comp/sequence is 4k and my render resolution is 720p, at some point AE or Premiere or Media Encoder says "Hey, we're scaling everything down, so let's render all the elements at half the resolution no matter what their scale is." So the 4k footage looks ok while the 720p graphics look like a pile of potatoes.

What can I do to have everything rendered at its full resolution?