Hi, I don't have a mechanical keyboard, but they seem very interesting.

I found some information about north-facing LEDs (they face up) and apparently there are also south-facing ones, which I guess means the opposite. What does center facing mean?

What are the advantages of Hall effect switches? I didn't know that they're used outside joysticks. What kinds of switches would you recommend for starting out/different price points?

What problems did you face with Rust? I love the language, but haven't really used it for that. I did do a bit of bare metal stuff, but that was some time ago. So most of my firmware experience is in C++.

Anything else that would be good to know?