Can an Ashkenazi or Sephardi Jew eat Yemenite matzo during Passover? (Or more generally, can Jews of other traditions partake of another tradition, not their own?)

ב"ה Shalom In general, a person is supposed to uphold the custom of his family. The Talmud stipulates that one must accept upon himself the customs of the place of his origin and also the customs of the place where he has arrived. This is not just viewed as a geographical origin also in regard to following the customs of our parents. (Pesachim 50b). Taking upon yourself a custom of another traditionת each one must be dealt with individually. In regard to Yemenite Matzot, i.e. soft Matzot, according to many great Rabbis, among them Rav Shlomo Zalman Oirbach zt"l, and former Chief Rabbi of Israel Rav Avraham Shapira zt"l, Askenazim must uphold their tradition of eating the hard, crispy Matzot as is the most common today as written in the Rema in the Shulchan Aruch ( סי' ת"ס:ד ) . However, as written by Machon Hatorah Veha'aretz ,(which also appears in the Hebrew counterpart of this website) , soft Matzot can be used for the ill, infirm , for the elderly or for young children who have difficulty eating regular matzot. Otherwise, as said, Ashkenazim must keep their custom. Some Rabbis hold, that this rule applies also for other Sephardim who had no such custom of soft Matzot. All the best