Q: Where does free will end?
It’s like you have purchased a ticket on a plane or a boat, and once you get on board with that you are going to its destination. So up until the time you got on board you were able to exercise free will, (actually you still can), but let’s look at this one piece at a time. There are two processes involved in this; one is deciding your destination, and the other is allowing, or disallowing, the flow—the flowering—of the Universe that will take you there.
Free will begins with your field of intention—the imaginative vision you put forth. But then your entire world, your entire field of experience begins to mold itself to that imagining; certainly in the nonphysical, pre-emergent realm where all things are assembled. And the only reason it doesn’t manifest entirely into your physical experience is all that contradictory thought that you allow.
Once you launch it forth you are driven by that energy field as well; your course is predetermined by your own imagination. In our boat or plane analogy you are the navigator and with your imagining of a destination for yourself you are setting the course. And then it’s like an autopilot. The Universe will continue to that destination so long as you stay in alignment with it.