The difficult part of the triangular shift was mainly achieving extreme precision in one's control over the mecha. If the mecha moved too quickly then both the mecha and the mecha master would have to withstand extremely massive pressure. The act of completing a triangular shift was already close to a complete turn around because an equilateral triangle with all three equal sides was made up of three congruent internal angles of sixty degrees each.
This could easily cause injuries to both the mecha and mecha master. If the speed was too slow, then the technique would lose its 'shifting' trait.
Thus a continuous triangular shift was very simple. However, it was still very difficult to properly utilize the triangular shift such that the mecha achieves a certain speed without the slightest imprecision.
The ability to launch a good triangular shift was the foundation of a high-grade mecha master's ability to perform a change of direction in the air.