When selecting mutiple files, pull-down menus in the left pane usually allow to set the selected tag to:
Delete/erase
Keep
Any of the pre-existing values from the list of files
The Genre tag seems to be an exception to this feature. It does provide as options:
Delete/erase
Keep
But the list of pre-existing tags does not appear. Instead is a very long list of (generally accepted?) tag values. If pre-existing values are not in the standard list, the desired Genre value has to be typed manually.
Am I missing something, or could this be a feature to implement, by showing at the top of the list those tags that are present (if any) in the selection of files, or include them within the alphabetical list of standard tag values?