Recently, I have bumped into the following user case several times: One screen is used permanently while the other one is only switched on from time to time (usually it is a TV which is only needed if a movie needs to be watched). When the second screen is on, Xfce makes a guess on how to configure it, which is quite good, but usually the user wants to change the configuration (for example the relative position of the screens). This configuration needs to be repeated whenever the display is switched off and on again. It would be great to have the possibility to manually configure a display setup, then save the whole settings into a profile and be able to select the whole set of settings whenever necessary. One could have a dropdown list of profiles with the functionality of loading, saving, deleting and applying any of them. In the long term one could extend this feature to automatic recognition of the connected screens and selecting the fitting profile (which needs to be appointed by the user once) automatically.
This has been implemented and released already: https://git.xfce.org/xfce/xfce4-settings/commit/?id=b692780cdce46447cebb4af410da5b0b355e6eb5