Already in 2012 in Acrobat XI a new feature was introduced which allows to store information from Output Preview (color value of separations or result of object inspector) as an annotation in the PDF page. To get this the user had to perform a Shift+Click on the page while the Output Preview window was open.
The use of the Shift key as hotkey was unfortunate since the shift key is also used for performing multiple selections with the Acrobat tool Edit Object or the PitStop Inspector. This was no longer possible while the Output Preview was open. Instead of selecting multiple objects Acrobat created unwanted annotations.
Adobe has solved this dilema now (after almost six years!) with the February Update of Acrobat DC 2018 by introducing a new option in the preferences. In the Page Display section the option Use Shift + Click for Multiple Selection with Output Preview can be enabled:
This changes the hotkey for the creation of annotations to Alt (Windows) or Option (Mac). This makes sense. However by default this option is disabled. Each user must himself enable this option in the preferences!