You say that, but: Nvidia's "blob" driver doesn't have CUDA, NVENC/NVDEC, nor DDC I2C support on FreeBSD — despite all of this functionality being specific to Nvidia's own hardware, and the support being present in the Linux blob, which runs on a relatively similar platform.

If the only differing bits were the portability framework, this would just be a matter of adding missing support. But it isn't — the FreeBSD object file Nvidia publishes lacks the internal symbols used by the Linux driver.