Does the code for insulin do anything else?
(There are some examples of molecules families. You have many variants of it encoded in the DNA, and each is optimized for a different task. IIRC the idea is that some molecule is used for two similar thing, then after a lot of generations by a random chance you get two copies of the code in the DNA, then after a lot of generations each copy is used for one task, then after a lot of generations each copy evolves to be optimized for it's task. See the variants in https://en.wikipedia.org/wiki/Hemoglobin#Types_in_humans and also the distant variant https://en.wikipedia.org/wiki/Myoglobin )
So... not "well known and understood" then - if it were, a definitive "yes" or "no" would be the appropriate answer.
Why produce insuulin if you can’t use it. The mere presence of that sequence may have consequences for other development. Some sequences may be if, then, else statements, there is so much we don’t understand.
We are playing russian roulette, except the number of bullets changes every round.
But we’ve done this before, “humans can’t possibly alter the global environment”. Even climate scientists were saying that until about 20 years ago.