I do not remember any talk on this forum of successful unlocking of a “USA” Qualcomm Samsung 9(+). I briefly searched https://forum.xda-developers.com/ without finding anything encouraging there.
- An example of a thread which goes quiet when no one can add anything useful https://forum.xda-developers.com/t/difference-between-g965u1-and-g965f-ds.3882676/
Some other threads in the forum.
My personal view – no problem being open about this – feel free to quote your sources.
You might edit your thread title to include USA, may attract USA comment.
Edit, unlocking the device is one thing but the /e/OS ROM is built for a quite different Exynos processor – this is the actual blocker.