So I've been working on a library in Rust to make it easier to work with theYahboom 4WD smart robot for the Raspberry Pi 4B. Been testing it with some version of Ubuntu? on the RPi4 from the company. It uses the rppal library for the lower level hardware stuff so should work anywhere it does, Wasn't really sure where it fits into your list but thought I'd let people know about it here in a issue and let you decided 😉

You can find it at:

https://github.com/Oxidized-Robots/rust_rpi_4wd_car

Still new project as you can see from the version number 0.0.10 but all the hardware works and I have several examples you can run. I'm still back engineer something to work with their exist remote control software plus working on a replacement for their Bluetooth/ TCP/ etc stuff that is fully open source. Questions, comments, suggestions, and help are all welcome 😃