Going to fourth density? Or fifth?

[zenmaster]

Are you saying that what we would perceive to be the passing of 700-ish years in a 3D/4D hybrid sphere is actually the "quantum leap" itself? In other words, "quantum leap" and "transitional period" are synonymous in your view?

No.

What is the difference between these two concepts? How long does it take for the "quantum leap" to occur, and what would be the evidence that it has occurred?

Quantum leap is when the planet is 4D "magnetized" for local use of 4D vibration. I'd expect that to not be transitional. The transitional period is where the sub-sub-logos makes use of the vibration through the corresponding level of consciousness.