I actually ended up writing a Rust program to change screen brightness through /proc myself. Previously, I used a Python script. Understandably, the Rust program is very significantly faster than Python, and I was surprised by the difference it made for interactive use (changing brightness by a scrolling keybind). For comparison, here are two iterations of the Python code, and the Rust code: https://gist.github.com/FreeFull/1e5873f0b13ec291158176db9d7...