Can someone explain the logic of the Render Resolution Percentage in the Properties->Render options? This makes no sense to me and does not work as expected. For one thing, changing the percentage to 50% still outputs an image at full rez, while the Image Viewer displays a full-size image that is cropped 50%. Worse than that, setting the percentage to anything other than 100% messes up the composite in numerous ways. It changes the size and position of roto-mattes, and it changes the motion and position of transformations controlled by tracking curves. Oddly, it does not affect a Planar Track node.
I have read other posts that suggest placing Scale nodes after each image source, and apparently each mask, track source, and transformation node in order to accommodate changes to the render resolution. That is insane to have to place a scale node after every operator in the script.
Why does it not simply reduce the size of the final output like any normal scale operation. Why does it have to affect everything in the composite? There seems to be no end to the bizarre logic at work in this software.