A BEL is the result of an animal receiving 2 copies of a gene, one gene from each parent. In that regard consider a BEL a recessive animal like a pied or an albino. The confusion comes from the fact , that one copy of the gene cause a visually different animal than a normal i.e., a mojave, a lesser, or a Vin Russo Het Leucistic. Those genes are basically variations of the same gene, so no matter how they are combined they produce a BEL. Each 2 gene combination of the leucistic genes produces a slightly different result. So when you breed a BEL to a normal you will only produce visually different animals. So if your BEL is a result of a mojave bred to a lesser, then statistically the resulting babies will be 50% - visual mojave's and 50% - visual lesser's. Since your normal parent doesn't carry either a mojave or lesser gene, you can not produce more BEL's, because they will only receive one BEL gene from their BEL parent, regardless of what went into making that parent a BEL. I hope this is helpful.
Mike Kelly