Allow tasks and activity series to be changed for future events. Leave prior as history, unchanged.
When reorganizing your future activities, you wish to change future events but leave the previous ones as a record of the history of any changes made to them. It is frustrating that if you change the series for future events planned, this impacts the time, duration and more of the previous ones, altering the history. Some previous events of the same event may have been canceled, delayed, swaped with others and that history should remain.