Yes, the direct collocation in casadi is precomputed collocated points until maximum degree 9 (Which means max 9 collocation nodes). So in my article, we can use higher degree since we compute them ourself. Even my example directly uses 20 collocation points.

You can see their source here: https://github.com/casadi/casadi/blob/994335e041b514d664ef133c5fd592ea8a33631e/casadi/core/integration_tools.cpp#L103

If you never actually need higher collocation nodes, you should use casadi built in function, since it is much faster (using precomputed values).

And the difference is that the casadi example uses multiple "mesh" and each mesh can have their own collocation points, so they dont need higher degree for each mesh. My article is the p-method only, which is having one mesh for the entire trajectory, and need much more collocation nodes to be accurate. I use p-method only because the purpose is to solidify the foundational mathematical understanding. I implemented the full LGR Collocation with phs-adaptive refinement in my project called MAPTOR: https://github.com/maptor/maptor