にとどまらず・に限らず: the difference
にとどまらずN1
Meaning
Not limited to, Not only...but also, Not stopping at
Past papers
Example
共感は人間にとどまらず、動物にも見られるものである。
Empathy is not limited to humans; it can also be seen in animals.
に限らずN2
Meaning
Not just, Not only… but also
Past papers
Tested once in past papers
Example
ラッシュアワーに限らず、電車にはあまり乗りたくない。
Not only during rush hour, but I don't really want to ride the train.
How to tell them apart
「にとどまらず」: crosses a boundary and spreads outward. For example, a fire that did not stop at the warehouse but reached the houses.
「に限らず」: just says 'not only A, B too', with no sense of spreading, as in 「若者に限らず高齢者も利用する」 (Not only young people but also older people use it).