Board Thread:Naruto Discussions/@comment-36755597-20180829215104/@comment-734582-20180901193834

A Kekkei Mora is basically the all-encompassing version of the blood line. IE, Rinne Sharingan is a combination of two separate bloodline abilities. It's the most complete and advanced form and hence, "kekkei mora". It's powers are beyond it's constituent parts and is the most complete version of that power. In other words, it's the undiluted power of the Chakra Fruit.

A Kekkei Tota is unclear, but so far has only been used in context of elemental releases. Rinnegan, though rare, is not Kekkei Tota. Other abilities like TSB's or black rods are neither. So it's definitely not linked to rarity by itself. If it's a combination of KKG, i would say that (E-)MS would be a qualifier, since it combines Sharingan, MS, and Susanoo. Sasuke adds Rinnegan on top of it, yet also does not have anything labelled as Kekkei Tota.

In other words, though never explicitly stated, i think it's a relatively safe assumption that Kekkei Tota refers to 3-element combinations exclusively.