The problem with those settings is that it enlarges the UI of certain elements that cannot otherwise be controlled, for instance the chat window UI, in particular the bottom buttons such as `General, Party, etc, will become bigger and there is no way to change that (which in itself seems like an oversight).

Also by using a default size on 100% on a scale of 150% does not reduce the size of the elements to the same size as if the scaling was set to 100%, it sets them to the baseline 150% scale which for is already quite big ne uses far too much screen real estate for my liking.