Looks like there is no simple way to add the Target term to the term pair via the Frequent words routine.
Perhaps that feature could be added here:
Probably there is a more logical/intuitive way/place for this task (adding term pairs from the Frequent words pane)?
Neither there is a way to search for source words in the project from within the Frequent words pane.
Can the user set the minimal fragment length?
alwayslockyourbike