That’s super insightful for what should be a basic requirement in calendar design. I’ve been doing something like that instinctively with family logistics, so when someone asks for a drive to school or work or yoga, I know this is three “events”: their actual thing, the buffer to arrive early for the drop, and if I’m picking them up, usually leaving before their shift ends. My personal calendar looks chaotic because of all these strange little events, but once you have two or three of these in a day, the overlaps get complicated fast. Margin/padding is a nice way for me to think of my own planning and be prepared when others generally put little thought in the dependencies of multiple events.