When to use the manual controls

Either Director 1 does it, or you do it with the manual controls in Arrange. There is no third path where you ask for something and the world quietly changes without either of those happening.

Both write to the same project, and both are equally real. Switching between them mid-build is normal.

The change is about behaviour rather than appearance — how something moves, what happens when you touch it, what the rules of the game are. That is code, and code is what Director 1 writes.

Or the change is large and repetitive: generate a landscape, put a player in the world, set up weather from nothing. Doing that by hand is slow and the result is not better for having been slow.

You can see what is wrong but you cannot describe it. A shoreline that is nearly right, a hillside where the trees look sprayed on, a walk speed that feels heavy — these are faster to fix with a slider and your own eyes than to write a sentence about.

You also want Arrange whenever the answer is "a bit more" or "not there, there". Dragging is a more precise instruction than any sentence.