Yes. You never threaten to resign. You conditionally promise to resign.

I had to make this conditional promise once, back in the nineties, as a junior person in a related industry. Because in the dot-com era developers like me were often simultaneously a babe-in-arms on a professional career level and also the only person who knew how to do the work that was being sold. I decided that if it came to it, I would not be the person having a hard time in court. The client understood better than my bosses and they changed the product. Took them a few minutes at most, but I have reason to believe that my decision made some ripples.

Nowadays I don’t let those issues surprise me: I believe in establishing specific ethical standards at the beginning of projects, because if you don’t do that, you don’t have a basis to robustly point to actions that put them at risk.