Deep edit not enabled when typing characters in a cell with typeahead functionality

I am trying to provide my business user the convenience of being able to navigate using tabs or arrows key with typeahead enabled for the columns. When the user navigates to a cell and type a character, the cell goes into edit mode but the user cannot use the arrow keys of the key board to select a value from set of the values shown using the typeahead editableCellTemplate. If the user navigates to a cell and types a character and then does a click on the cell, then the user can use arrow keys of the key board to select a value. I see the cell does not go into deep edit unless I click on the cell. Is there a way to make the cell go into deep edit without having the user to click on the cell again ?

The plunker http://plnkr.co/edit/Nv3jWoofg2rol5M6eUpk shows the issue.

Please let me know.