It is indeed possible to make a Cube file with the configuration (although not 100% always - it requires that the configuration is also present on the LabFloor).
About the wavefunctions, there is an additional complication since the Cube file format is for real data only, whereas the wavefunction is complex. So one needs to implement the possibility for the user to choose the real part, imaginary part, psi^2, or perhaps sqrt(psi^2).
I'll post an updated plugin here a bit later - I have a prototype already lying around but I need to update it a bit.