Difference between lesser platinum & butter

[jason79]

Resurrecting an old thread, I know, but...
Here's my only issue with calling them the same:

Although breeding a lesser to a butter WILL give you a BEL, if you breed that BEL to a normal, you still have a 25% chance of producing a normal...which means the BEL you have is NOT a super.
If you produce a super butter BEL, you have 0% chance of producing a normal with it's offspring.

Compatible, and very similar- but not the same.

Is this proven that a lesser/Butter BEL produces normals but a Lesser/Lesser or Butter/Butter BEL does not?