I’d think that you’d want this “live matching” built into a Data Entry for a new person too.
While you’re entering a new person, Gramps tells you what possible people already exist and might save you from creating a duplicate.
And you’d want some fuzziness in the search too. But the old-fashioned SoundEx is only good for English names, not so much for other languages with accented unicode letters. So Double Metaphone or Beider-Morse Phonetic Matching would give fewer false positives.