I actually think maybe upscale render texture would be also good
I made a short video demonstrating the differences.
The squares of the gray grid in the background are 1px each, 84x48 upscaled to 840x480. The left side is the scene view, the right one the game view.
- Without Upscaling or Pixel Snapping: the pixel perfect component has essentially no effect besides changing the cameras size.
- With Pixel Snapping: scaling the sprite still won't cause the entire pixel to be filled, moving works fine though.
- With Upscaled Render texture: both scaling and moving the sprite fills the entire pixel.