how to compare method of moment and MLFMM on CST?

I want to calculate E-field monitor on the surface of a structure (PEC) from the far field gain pattern of an antenna(2 GHz) imported as farfield source on CST MWS.

For this I use the I-solver and i want to know:

what's the iterative MoM implemented on CST?

how the results from MLFMM are linked to the MoM ones,
and what parameter i have to change(accuracy of solutor, box size of MLFMM , mesh size... ) for have the convergence from MLFMM to MoM ?