Basically I would approach this as a general framework. For example,
"I have 2' between the top of the pots and the screen."
This is a pic from
@Cool_Beans current grow
So that 2' will become all stalks in your example. I think Beans has less headroom than you though.
You can see where he kinda forced the plant to fit his space.
You may very well change this next grow after you see how it goes, but that LST of pulling branches down and either keeping the middles long and forcing them to the corners, or topping to get the branch structure you want is what you need to plan for.
Knowing then what he knows now, beans probably would have vegged a bit longer to get a wider canopy to grab all the light. But every plant is different, and your grow will be different from his due to many factors, including the light.
So see where you want to be, and follow your gut as to what stays and what gets trimmed as you continue to veg. It does not have to be perfect to get a good harvest. But you will learn a ton from this.
In terms of stretch, you can use that to your advantage to get the whole net/canopy filled up.