Yes, but from watching the video it's pretty clear to me that he is not using pre-determined movements but rather set coordinates with calculated movements, probably using a model that knows the arm's geometry and limitations. But since he doesn't discuss how it's modelled and implemented it doesn't help much. I've been using the Java Mindstorms OS, LejOS quite a lot and it has great abstractions for many robotics tasks. But again, unfortunately, they are mostly aimed at controlling/pathfinding in 2D, not 3D. This is just to say that your suggestion to create an open source python project is probably the best way to go about it. Good luck!
From a quick look, this looks promising. And you're right, doing this math from scratch is a monumental task. I've been a developer for 2 decades but since I've mostly been doing high level work, I still find robotics really difficult and I'm always struggling to find the right abstractions. But they already exist and it's just a question of finding those that match the problem at hand.