MKS XDrive Mini Guide: Set up, Tuning & Arduino

I started a DIY robot dog project and quickly realized I’d need at least 12 FOC drivers for it—actually 16, since I’m going for a wheeled-quadruped design. At $150+ per unit for an ODrive, the electronics alone would cost between $1, 800 and $2, 400. That’s a total dealbreaker for me and most hobby builds. MJbots moteus makes it slightly more affordable, but it's still too expensive and significantly less powerful. So, I decided to play "AliExpress roulette" and try the MKS X Drive Mini. It’s a $35 ODrive replica that claims 3kW of power on paper, but it ships with almost no documentation and several integration "surprises." Since I couldn't find a decent guide on how to actually use it, I decided to make one myself. This was originally intended to be Part 1 of a larger "cheap robotics actuator" series, but the guide became so detailed that I decided to launch it as a standalone project.