Datepicker: Unable to enter date manually

As seen from demo page: https://react.lightningdesignsystem.com/components/date-pickers/

Click on the date picker component and start entering a date using the keyboard

Expected: the characters should be displayed as typed in, date picker component should close, user should be able to continue to enter numeric and date format characters based on locale ( 0-9 / - etc).

Actual: As soon as first numeric character is entered, the date is auto-completed to the first day of the first month of this year. Enter "1" and it fills in "1/1/2021". Enter "2" and it fills in "2/1/2021". You cannot modify this date without it continuing to change it on you.

This was previously reported 2 years ago but has not been properly resolved.
https://github.com/salesforce/design-system-react/issues/2285

Reproduce the issue on the date picker demo page at https://react.lightningsdesignsystem.com/components/date-pickers/ by entering a date with the keyboard. Then trace the date picker implementation and its existing behavior for locale-specific input; done means characters remain editable while typing, the picker closes appropriately, and numeric or date-format characters can be entered without unwanted auto-completion.