Awesome, thanks!
I thought I had replied earlier but apparently my click on the "post" button never registered so I came back to it still sitting in the text box -_-
Anyhow, I'm just reporting back to confirm that the mod is indeed working as intended, I just had to adjust the values to give me portraits that were more consistent with the in-game description! It can also be tricky depending on the specifics of the slave seeing how they're first filtered by 3 different age ranges, the amount of combinations just on the 4 included parameters makes it easy to just not have a matching portrait. I have 4000 images and some of my folders literally have only a single portrait. Makes sense though, I reckon finding appropriate art for certain age groups of certain creatures (like orcs) could be pretty hard ^_^.
Anyway, thanks again and happy ... slave owning?