You must be out of your mind. The kid has Borderline Personality Disorder, is clearly having symptoms such as threatening with suicide, self-mutilation and dissociation, and you recommend Mindfulness exercises?
No, I recommended that he call his clinic.
I suggested these exercises if for whatever reason, he got disconnected. Mindfulness is a big part of DBT... which is the main therapy for BPD... and is all about being present. Which helps to counteract disassociation.
Socionics is a dangerous thing for a woman like me to have, but I have it.
Model G: IEI-CNHD
Model A: Most likely ISFx
MBTI: ISFP-A
Enneagram: 9w8 5w6 2w1
AP: VELF 4231
PY: FEVL