Reply To: Minhag of not saying Tachnun issue

of course ask a Posek

i believe the velt is generally noheig to follow the Minhag of the shul you are davening in, regardless of your family or cultural Minhag.

i think that is the Halacha for something that is visible as to what you are doing, such as Tachanun or saying Kaddish

something private like the nusach of the silent Shemoneh Esrei is different.