Differing clan badge from other side of the families Tartan

[Karl R]

Is this bad taste? To take a Macneil tartan, and pin it with a MacQueen Pin? Maternal and Paternal sides of my family

If you're a fan of two different football teams (or basketball teams, or baseball teams, or hockey teams), would you wear the sweatshirt for one team and put a pin on it for the other team?

It's similar. By wearing the tartan and/or the badge, you're showing your allegiance to the clan. If you want to show your connection to both sides of the family, it's better to do so on different days.