This is a scenario:
A form requires an Address Number and Address Street, but this is separated in two form fields. A user that is using the manual fallback can only fill the Address Number and Address Street combined. 

Because the form won't parse as a result, the user will have to focus the Address Street field and remove the Address Number from it. 

There are two possible clues that tell us that the user wants to go back to the keyboard. It's up to eng to see which state is easier to identify. 

Clue 1:
The user repositions the cursor into a field that has already been filled using manual fallback. 

Clue 2:
The user partially selects/ highlights characters of the string in a field that has already been filled using manual fallback. 


Based on which of the 2 clues is easier for eng to identify we will use one to switch to the keyboard.