Rust bindings are at the bottom of the readme: https://github.com/semio-ai/vkfft-rs

Also Python: https://github.com/vincefn/pyvkfft

getiin' old, it's the second time today I miss the obvious, clearly visible, information :-(

> If you put together the GPU time + GPU upload & download, is it faster than CPU overall?

That always depends on sample size and the hardware you use.

And like for all those kind of problems on it also depends on the parallelizability of the computation you are doing.