MMDA is not 3-methoxy-MDA, it is 3-methoxy-4,5-methylenedioxyamphetamine or 5-methoxy-MDA. Confusing you might say, but notice that even though the "4,5-methylenedioxyamphetamine" part abbreviates to MDA as well it is not the same since the numbering changes it. MDA is 3,4-MDA.
I would personally be pretty interested in MMDA-2 but it does not have a methoxy on the 2-position of MDA... on MDA itself its the 6-position though at the moment you attach it you have to re-number it making the 6 the 2 all of a sudden and making the 3,4 a 4,5 again.