Q. Thank you very much for your response. (See question 1442).
Would the same be if my son in law came to my home for Shimi Atzeret, when I do not eat in the sukkah, would he not eat in the Sukkah to follow my custom (when his custom is to eat in the sukkah)?
Thank you,
A kesiva V’chasima Tova.

A. Horav Shlomo Miller’s Shlit’a opinion is that on that case he would have to follow his tradition and eat in the suka, to comply with the mitzva of eating there.
It is not the same doing an unnecessary mitzva according to your minhag, to not complying with a necessary mitzva, which is your son in law’s situation.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a.