Total Amount not shown as required for Import Contributions - update existing contributions

"Total Amount" is a required field for Import Contributions - update existing contributions but it is not asterisked and shown in red as "Financial Type" and other required fields are.

This is rather frustrating if you are using 'update existing contributions' to import new or change existing data in core or custom contribution fields other than total amount. It can mean you have to do a second contributions export and a second data matching step to get a CSV file you can actually import into civicrm.