It has already been established that generally, Ashkenazim stand for Kaddish, while Sephardim sit, unless they were already standing. (That said, i have observed Sefardim who davka sit for kaddish.)

What would an Ashkenazi do in a Sfardi shul? Am i required to davka stand? On the other extreme, is it even permissible to go against the minhag hamakom of sitting?
The reverse - should a Sfardi at an Ashkenazi shul stand or sit for Kaddish?