Butters and Lessers, are there distinctions?

[Hannahshissyfix]

But, do we have any proof of lessers/butters being the same thing? And any proof of general consensus being they are the same?

Absolutely! As has been pointed out over and over, besides normal variations within any of the same morph, they both look the same and do the same thing when added to any combo. I don't see how it gets any clearer that they're the same thing. It's not like someone looking at a mojave and a phantom and not being able to see a difference which isn't that drastic but we know a super Mojo and a super phantom look completely different.