Copying the fingers is the most common operation. Every cons/decons requires copying one of the fingers. Operations that propagate deeper into the tree are lazy

Copying the fingers is the most common operation. Every cons/decons requires copying one of the fingers. Operations that propagate deeper into the tree are lazy, so the primary factor affecting performance of common operations is time required to copy one of the fingers. The result of using a higher branching factor would be copying a larger memory block many times.