Hi PP,
Ya, those font list are custom code by Divi and we are unable to send the font list there. So what you have done is a right step. However if you need there are some other options as well.
1. You can assign the font to our pre defined elements from font assign section. And the font should be assign if those custom elements are using the same elements. (The way you assign to a tag)
2. If you know bit of css, you can write custom element to assign the font.
3. This is new feature from 4.6. Usually divi accepts custom class. You can keep the same class as the name you defined for the font when uploading.
Hope this helps.
Thanks