I get frustrated with the way Tableau breaks lines as they extend across panes (picture attached). I often want to show a monthly view across multiple years and find the line breaks at each year mark. If you add Quarters in it gets even more choppy.
You can get around this by using continuous date fields instead of discreet, but then you lose the nice way that Tableau organizes discreet dates (break lines at the end of each year, for instance).
I think there should be a way to allow lines to connect across pane borders.