Mix and match HD and Pixel-Perfect?

I’m making a top-down 2D RPG, and I want to have a pixel-art overworld, but HD UI. I have the overworld itself working just fine using a pixel-perfect renderer, with no filtering and all that:

The overworld is rendering on the main camera, and everything it’s supposed to render lives on the “Default” layer:

I also have a UI element on the UI layer, and a camera UICamera that looks like this:


and it’s only rendering things on the UI layer, and it’s a “standard” (non-pixelperfect) camera.

Despite this, it appears to be rendering at the same sample->upscale resolution as the main camera:

The large UI element in the center of the screen (a pop-up text box) should be a smooth texture:

Anyone know how to fix what I’m trying to do?

Additional information:
I know the UI element is rendering on the UI camera because when I disable the UI camera, the element ceases to render.