There is support for Fog and reflections are determined by the reflectance of the BasePart 
I run a Macbook Pro M4 Max, so the single-threaded score is quite high (Which is important since the renderer is currently only single-threaded). That allows me to get pretty good performance out of it vs other machines.
I have, however, been doing regular sanity checks on my machine against other rendering solutions [RetroRaster and BeauChavelet], of which all have very different architectures, and so far there are no obvious issues with the performance.