Would be great to have a feature that remembers a set of styles (arrows coming from boxes for example with colors) that I can pick and reuse.
Even though it is not exactly what you are requesting... have you tried the "Object > Save objects to file" and "Load objects from file" options from the editor menu bar? All elements drawn onto the current screenshot will be exported to a file and can be imported again when editing another screenshot.
Might be a handy workaround for now.
I also would like to see this feature. To be able to select saved styles. For example Hightlighting with colors, Counter, .... with saved all of the settings.