Nudge Region/Event Length Right by Beat
Make the selected event longer by one beat. One of the particular oddities of the Logic Pro documentation. The only mention of nudging by length is in reference to movies (soundtrack) and in the Score Editor.
Rather than creating a separate key command for this I would simply use the ‘Set Nudge Value to Beat ⌃⌥B’ and then use the ‘Nudge Region/Event Length Right by Nudge Value ⌥⇧→’ command.
You can move selected notes in the Piano Roll Editor to change their time position. When you move notes, they move according to the current Snap value for the Piano Roll Editor.