I figured out how to make downloaded mods work on a mac.

1. go to customize on any character
2. then select custom body and click select folders
3. after that, click on any of the user:// things. This opens a window where you copy the path
4. then go to finder and shift command g and paste the path but delete the last /portraits or /bodies
5. click the name at the top and drag the folder to the side of your finder for easier access
6. from there, just place the mods you want to use into the mods folder
7. add them in the mod window ingame

This works for some mods that say it requires the EML (Which I haven't found a way to make work on a mac) Specifically, it works for the Conquest tweaks. I haven't tested much else