Best case scenario it will be awhile before you need to worry about eggs. I wouldn't worry much until the female starts to expand. My concern would be what would I sell the babies as? If you are keeping them all it is not really an issue, but you have mystic and phantom involved in the same pairing? How exactly are you going to know what you got?

If it is white you know it is lesser/mystic
If it is a phantom/mystic sell as a pet?
Single gene phantom or mystic? good luck telling the difference

this is kind of like mixing butters and lessers.