Early on you learn outside as がい alongside inside ない
You then learn outside, extremity and to be disconnected as そと、はずれ、外れる
This is followed shortly by 外人 as がいじん
I would recommend that がいじん is introduced later, possibly once はず はずれ、はずれる are guru level.
Alternatively はず needs to be accepted as vocabulary for the single kanji 外 with a warning about the multiple meanings.
Just my two cents