.. only one caveat, DFC.
I read your post to indicate that you plot only a final loaded point for specific loading cases .. no problem with that.
If you are looking to see the variation of CG as load varies, eg with fuel burn, that is most conveniently done on a graph of weight against moment or IU with a CG overlay.
Not so easily done on a graph of weight against CG unless you continually redo the sums and replot the one point for each exercise.