The US will stop you from using it with sanctions. As a US citizen anywhere in the world intentionally circumventing sanctions grant you up to 20 years prison time.
That’s just the short version not to speak of secondary sanctions and further mechanisms which take place then.
Won't EU companies just announce they've "developed" a new model named Komo, and then we can just use that? Or is the US just going to straight up prosecute plebs for using any model not owned by one of the 5 Americans?