I’ve implemented 3D rotation matrices (see the implementation here) and bounded variables (as we discussed before), but it’s easy to add your own. It should be very straightforward to use variables from Manifolds.jl in NLLSsolver.jl. You just need to overload the NLLSsolver.update method for the particular variable type.
I’m happy to discuss it further. Please message me direct.
I’m slowly adding more solvers. I may try to add that one. But it’s a Euclidean problem.