It all depends on how you take the word.
Some may take offense, while others may not see it as a big deal.
I felt the spirit of what Archae meant by "mutt" so I took it as funny. Archae was light-hearted about it so I followed Archae's lead.
And I'm a dog lover who doesn't see anything wrong with mutts. I would always take a mutt from the pound instead of paying through the nose for a "pure breed".
Nevertheless I understand your stance on the matter.
Mixed is another way of saying it & easier to pronounce. I use Multiethnic because it's more accurate than saying Multiracial (which itself is more accurate than Biracial). Ethnicity covers all those little groups within the "races".
But things get problematic when ethnicity & nationality collide.
There are people who are ethnically Germanmeaning their ancestors formed their gene pools/phenotypes/cultures in that region over centuries.
Then there are people who are German by nationalitymeaning they were just born there.
There are people who ethnically Sudanese who are born in Germany. This would make them German by nationality but Sudanese by ethnicity.
Lots of British-by-nationality, Indian-by-ethnicity folks over in the U.K.
In America, there's the situation with the ethnically Chinese, American-born folks vs. the ethnically Chinese, American-immigrated folks vs. the ethnically Chinese, American-born back 4 generations folks. The ABCs American-born Chinese, the FOBs Fresh Off the Boat, & those whose roots in America go back to the 1800s & the railroads. Some of them may not speak Chinese anymore or even carry Chinese first names while others speak virtually ONLY Chinese with limited English & live only in Chinatowns while others may be bilingual with Chinese & English carrying both Chinese first & last names. Some may see a connection between all of those groups while others may be distancing themselves culturally from their ethnic Chinese roots. It's complicated.
Add more fuel to the fire if one of those Chinese is mixed with Whites or Blacks or different types of Asians or the already mutliethnic Hispanics.
Biologically you are what you are end of story.
Socially you will be classified based on how others perceive you.
Personally you may have your own interpretation of your identity independent of the biological or socio-political realities.
There're so many answers. This is what makes the issue so highly charged.
John Lucas