See the list at the end of https://fpmon.github.io/fingerprinting-monitor/files/FPMON.pdf:

• window.devicePixelRatio
• window.innerWidth
• window.innerHeight
• window.emit
• window.outerWidth
• window.outerHeight
• screen.colorDepth
• screen.width
• screen.availWidth
• screen.availHeight
• screen.pixelDepth
• screen.height
• screen.availTop
• screen.availLeft
• screen.deviceXDPI
• screen.logicalXDPI
• screen.fontSmoothingEnabled
• screen.screenInfo
• navigator.orientation

The problem is that we might create inconsistencies and/or break pages.