That would be pretty nice to have, really. I've forgotten to adjust the max charge after traveling, as well. Scheduled charging already is done on a location basis.
Something as simple as a message that triggers if you put the car in park at home when the max charge is 100% would be nice. "You're home. Would you like to set your maximum charge to less that 100%?", along with a "Yes" button that opens the charge settings, a "No" button to dismiss the message, and maybe a "Disable Reminder" button for those that just like to keep their max charge at 100%.
It's hardly a major deal, but it would be nice to have.