Is it permissible to consider a paternal cousin (son of one's paternal uncle) as a mahram if marriage to the paternal uncle's daughter is not allowed according to local traditions?

A mahram is someone whom a woman is permanently forbidden to marry due to kinship, suckling (رضاع), or marital affinity. This is derived from Islamic law, not from customs or traditions. Surat An-Nisa (Chapter 4 of the Quran) mentions the women who are forbidden to men. A woman's mahrams by lineage are: her son, her father, her brother, her brother's son, her sister's son, her paternal uncle, and her maternal uncle. The same applies to mahrams by suckling. As for her paternal cousin (ibn 'ammiha), he is not her mahram; she must observe hijab in front of him like any other non-mahram man. No one has the right to permit what Allah has forbidden or to forbid what He has permitted. Surat An-Nur (Chapter 24 of the Quran) mentions those before whom a woman is permitted to display her adornment, and the paternal cousin is not mentioned because he is not among her mahrams.