This is my experience from a Genus bar appointment regarding this issue.
My computer had obvious imperfections (bottom part of chassis is loose, a knocking sound coming from the bottom of the lcd display when i tilt the computer) originating from manufacturing, which I asked the genius to check and mitigate if possible. But the main purpose of my visit was to run the SSD firmware update needed for the 13" nTB 2017 macbook pro models as I wanted to get done with it.
The genius employees were generally rude, and told me my computer is not eligible for the replacement program. I insisted they run the check itself, and that indicated that the computer was indeed defective and the firmware update had to be done. 5 days later, I go to the bar to collect my computer, which the employee is bringing to me open, using it as a tray for her iPad (iPad on being left the keyboard).
The computer was in its original state (nothing has been done to it on the outside and it still runs my OS installation with all my files), and when i noticed and told them, they tell me that they run the ssd firmware utility and it did not work for my laptop. Then, on their own, they offered to try again.
I asked what would change now? Does the utility misbehave? Maybe you forgot to run it in the first time? She replied that they did not forget and whether I want to leave it with them again.
I did not think much about it and I left it there, but now that I know that they could lie about it being fixed, I do not trust them anymore with my computer. How can I check that the SSD firmware has indeed been updated? Do I have to try another store to run the utility again?
Btw, anyone want to buy a slightly used Macbook Pro 13" 2017 with 16gb of ram? (an all the rest of my Apple gear?

)