Apologies, I wrote that incorrectly. We found that in some of our GUI windows, which have two static sizes, a line would appear based on the window size, suggesting snapping. This affected how we handled clip bounds for background images, with the line appearing in the clipped regions of the image.
We observed something similar with the Software Renderer on Windows. Although I could not reproduce the issue with Direct2D, it seemed to be influenced by the Windows DPI setting (What I mean by doesn’t rescale). I thought this might be something similar and could be useful.