With that system compared to mine there is greater distance between plants so they must be bigger first of all. my clones are 3 -4 inches.
Then my clones are maximum of 8 inches apart more like 7 sideways and about 8-9 vertically.
this way you flower earlier from the clone getting rootes.
Also i had holes in the sides of pots for the clones to stick out from towards the bulb. even thougfh most end up growing vertically untill the weight of the buds pulls them down.
For which you need string from the ceiling to support each and every bud/clone.from the book shelf -shelves.as well as support to prevent pots falling over.
That system didnt seem to have pandafilm to block light in from the outside. for mine, every bookshelf is surrounded by pandafilm, even underneath to prevent light stress.
Each bookself solo when you join them up the light doesnt get in.