why big design of 'Law of One' base on quantum mechanism in our 3rd density

[Infinite Unity]

The 3rd density is a veiled density where the true infinite nature of the universe is hidden from our conscious minds. Essentially this is done for a reason to encourage beings in our density to make the choice between two paths, a positive and a negative.

When trying to understand the more infinite workings of the universe I try to model it more as an intelligent being or consciousness that creates circumstances to teach us lessons on how to become more loving. Models of physics for me don't seem to capture the intelligent nature of reality.

In the Law of One Ra mentions Reciprocal System Theory, which was invented by Dewey B. Larson. You might find that interesting if you are looking for scientific stuff.

I agree the Creation is(the why) Created due to the parameters, of Love. The how is through function/mechanisms(organisms). Think of how the body, in many ways is relatable to devices. In this way, we are exactly what you see, and in the same stroke. Nothing like it at all. Its like an pro-echo/vibration, and a con-echo/vibration(reflector/reflection). Everything that is, is Unity. Everything is in some way/form/understanding relatable to all. The very essence of it, can only exist due to the reflector/reflection of all other.

Or in other words One motion explains all motion. One form, contains all forms.

The quantum world is not disconnected from our experience. Due to the illusion, and how we experience it would seem so, but separation does not exist. The illusion of separation does, to our perception. The quantum world is apart/is the building blocks of this experience. What gives rise to atoms, electrons, and etc. The quantum.