Facing non-merging walls in Collatz procedure using series of pseudo-tuples

The Collatz procedure generates two types of fully or partially non-merging walls, one ending with an even number, the other an an odd number multiple of 3.

The "tendency to merge" of any number has to be limited. The procedure contains a mechanism to do so.

First, some pairs of tuples iterate into another pair instead of merging. More precisely, series of preliminary pairs end up merging, but many "merge opportunities" are lost.

Second, there are series of preliminary pairs that do not merge in the end, implying more "merge opportunities" lost.

Interestingly, the convergent and divergent series alternate in so-called "triangles", before being segregated. The diverging series are not easy to spot, as each side is in a different part of the tree.

In the figure, the colors show the type of segment each number belongs to. It is not uncommon for converging series to follow another one as the last pair forms a even triplet that merge into a preliminary pair. This helps the effort to face the non-merging wall.

Note that all green numbers show a pattern about their last digit.

A triangle made of converging series of preliminary pairs forming diverging series with other ones