Hello Michael,
Thanks for the update.
The SfDateRangepicker component is based on a single input where it is difficult to predict the customers input is for the startdate or end date. This would be easily predictable if it is based on two inputs.
However, however in scenarios of selecting both the start and the end dates it would be difficult for the users who has to select start date twice, if we make it possible to alter the end date alone as per your request. So it will be appropriate for the users to select both the start and the end date at times of selecting the range, or the user can alter the end date using the input element by typing the end date manually instead of using the calendar to select the dates.
Kindly reach us for more queries.
Regards,
Joseph Christ Nithin I