Bad boundaries description or tests

It seems there are no tests like this, and it's highly sensitive to task complexity.

fuzzy_string_match("apple", "appxxxle", 3) == True  # remove 'xxx'
fuzzy_string_match("apple", "ape", 2) == True       # insert 'pl' inside

fuzzy_string_match("fuzzy", "fuzy", 1) == True # not 2 like in your tests (insert single 'z' inside)