Access BaseMatrix information obtained from static condensation

Hi,

I have a simple question regarding ngsolve.la.BaseMatrix.

I am following the tutorial 1.4 Static Condensation and I’d like to use the following matrices in Scipy

a.harmonic_extension a.harmonic_extension_trans a.inner_solve a.mat.Inverse(freedofs=fes.FreeDofs(coupling=True))
but I am not sure how to access the matrix information.
.
I know for a BilinearForm, we can use a.mat.COO() to access the sparse matrix information as shown in Interfacing to numpy/scipy. But the matrices I mentioned above do not have a COO method. Would you please tell me what I should do? Thank you.

Nick