Add the ability to "Create New" record WITHIN the editable grid. The reason NO ONE uses the MSFT editable grids is because they're impractical due to the fact you can't create an INLINE new record. You shouldn't have to click the "+" then fill out a full form or Quick Create with information to get a new record.

The user should be able to click the "+", a new row appears at the top of the editable grid. User fills out the information. User clicks a Save button on the row. And the new record is now saved.

This is a basic function that partners have been able to easily write code to do. Microsoft, please implement this as a default option.