Merge Vertices & Loop Cut In the examples I have attached. I am merging at centre those 3 vertices, and when I try to do a loop cut it stops at the loop cut, and does not go to the tip of my mesh. But If I grab the same vertices and scale to 0, they merge, at centre of the middle vertex, and when I perform loop cut it does indeed go all around. So I'd like to understand what does it have a different result, scaling to 0, and merging to centre.

Thank you.
Scaling to 0 does not affect the underlying topology of your mesh, meaning that you still have the original 3 points, and all your faces are still quads, in your mesh. So the loop cut can be completed. 

However, when you merge vertices, this changes the topology and effectively creates only 1 vertex out of the 3 original, thus creating triangular faces that cause the loop cut to stop when it hits a triangle.