As someone who wouldn't even know if a heat shield is upside down or the location of every single screw, what should I do if I was to encounter this situation?
Never mind what you should do.
What would you in fact do? You are far and away the best predictor of that based on your self-knowledge.
Flagellate yourself endlessly and engage in an email/telephone struggle with MSI customer service?
On the other hand, you may be an "easy going" type whose blood pressure would barely move.
Are you the type who might go to considerable trouble or expense to avoid issues or confrontation generally in your day to day life?
Unfortunately, there is no way you can get even a semi-accurate idea of what your experience with MSI customer service might be. The chances of a bad experience are likely between 1 and 50 percent. What good does that do you?
You can and would get many negative anecdotes about Lenovo, HP, Dell, Asus, Gigabyte, and the rest of them.
I don't know the nature of the problem with your PC. It may well be that it will cost you 50 or 100 to ship it back. It MIGHT be fixable for say under 200 in cash at a local repair outfit. I'd certainly consider that. That would likely be quicker as well. But your local guy could have no talent at all.
There aren't any good solutions for you. Some will be worse than others, but there's little way of knowing in advance.