Selecting basic oil processing, it looks like this.
изображение.png (235.65 KiB) Viewed 1247 times
When flipping it horizontally, heat connection stays in place, while pipe connections flip. Result: they overlap.
изображение.png (239.31 KiB) Viewed 1247 times
If instead it is flipped vertically, pipe connections are flipped vertically, but heat connections are the same as if they were rotated 180 degrees. Again, they overlap.
изображение.png (239 KiB) Viewed 1247 times
This is not just some theoretical scenario, and is something i've encountered in some mods. Even if the overlap was fixed, the inability of heat connections to flip would still affect certain things.