Testing this plugin as it comes with 1.2.0-a3, it's working mostly very well even for MHX2 exports. There is only one major problem, namely the size and firmness of breasts tends to be maximized way too often.
Setting "max deviation from default" to the left-most position gives BreastSize 1.0 and BreastFirmness 1.0 for 100% of characters every time and setting max deviation slider all the way to the right still gives size 1.0 and firmness 1.0 for just about 50% of generated characters, regardless of gender. Values < 0.5 are rare, seen for maybe 10% of characters. All other modifiers seem to be randomized correctly without any bias as far as I can tell.
I suppose getting very large breasts for the generated characters might be desirable for some users and of course I can just manually set a smaller size and then disable randomization of breast but I would really like some natural variation also in this regard. Actually it would be best to be allowed to set a minimum and maximum for breast size just like you have for the macro settings. Going further with development, firmness could be made to inversely correlate with age possibly by a "prefer natural anatomy" switch.
One thing to massively improve convenience of this plug-in would be a possibility to save the customized settings to a separate file so that you could have predefined selections of allowed clothes, hairs and other features for your chosen groups of characters. It is quite tedious to go through all the checkboxes for each new session to avoid getting ladies with a half bald head or a group of men with ponytails and braided princess hair
