It seems transparent geometry isn't being path traced (or if they are, they immediately terminate the ray on hit and applying the same trick as in their rasterizer)
No, it doesn't. Not entirely anyway. All the light transport is calculated using path tracing but primary visibility is still using the rasterizer.
https://www.nvidia.com/en-au/geforce/news/cyberpunk-2077-ray...
Nvidia's own announcement shows the path tracing overdrive mode is still tracing rays from a G-buffer, which would've been generated with the rasterizer.
I actually don't think Blender does "full ray tracing" exactly either, or at least at some point it didn't. At least to the point where you do get some rasterization artifacts, like being able to see the polygons on the edge of objects. That's probably about as good as you can get. Combined with a "nanite" like technology, it's probably not much of a problem.
The path tracing mode mentioned here however, does "full raytracing" like blender does (outside of a few exceptions such as particles). Same with Portal RTX, Quake RTX and a few others.