Traps in arguments when mentioning ''nature'' and avoiding natural fallacy?

When I read arguments where certain appeal to nature or naturalistic fallacy is noticed by participants, sometimes there is a tendency to bring up other more obvious example of these types of fallacies, show how absurd it sounds and continue the argument in other direction without any further argumentation regarding the naturalistic statement.
For example, I’ve read or overheard discussions about traditions and sexuality. At one point of discussion someone brought up
‘Judging by majority of animals, especially great apes and genetically close animals, humans most likely are sexually polygamous by nature.’
‘Oh, that’s a naturalistic/appeal to nature fallacy. It also natural to kill someone from your own species or steal it’s food, but we don’t do that.’
Or other time regarding options of diets:
‘It seems that humans evolutionary and biologically are opportunistic omnivores’
’Natural doesn’t mean anything. It’s just a fallacy. It is also natural kill the animal you eat by bare hands and eat it raw.’

While I can understood that in those cases ''naturalness'' automatically didn’t make it right, good or preferential, I can’t understand why ''naturalness'' couldn’t NOT be one of the 'reference of points or benchmarks in discussions regarding medicine, health, anthropology, sociology etc? Where is the line?

Is it then a natural fallacy to question invention’s or innovation’s effect on human even if it SEEMS at first glance harmless, but goes against (or at least is unclear regarding) some of the genetical (natural) realities as we understand them now?
Is it a natural fallacy to ask:

As far as we know, humans genetically are omnivorous. What does it cost us to go against this?

We most likely are genetically inclined to live in groups of few hundred people at very max. What does it cost to do otherwise?

We are very likely sexually polygamous by genetics. What does it cost us to live in monogamous relationships? etc.

I have seen that conversations often stop before those kinds of questions just because someone found ''natural fallacy’’. What then would be more correct way to introduce such an angle in argument without it getting automatically labeled and abandoned?

The objection "Oh, that’s a naturalistic/appeal to nature fallacy" is misplaced if used for the statement "Judging by majority of animals, especially great apes and genetically close animals, humans most likely are sexually polygamous by nature". This is because the statement is NOT making any claims to moral right or wrongness; it is simply stating a fact (or a hypothesis). If the statement made a moral judgement, THEN it would be fallacious. For example,

Judging by majority of animals, especially great apes and genetically close animals, humans most likely are sexually polygamous by nature. Therefore, we should embrace that nature.

You ask if the following is fallacious:

As far as we know, humans genetically are omnivorous. What does it cost us to go against this?

If one were picky, they could argue that it begs the question that there is a cost (perhaps "Is there a cost to go against this?" would be better phrased), but this does not trigger an appeal to nature. If they did say it was an appeal to nature, they would simply be wrong and be guilty for abandoning the argument based on that reasoning.