Where would you drill the holes for the plants?

I would do 4 holes.Since aeroponic will give you huge plants, you will have space Problems with 6. I'm am doing only 2 plants and they fill up 1m2 . Perhaps 3 holes would do it too, but I feel the spacing between them would be to close. But aeroponic rocks, what pump you are going to buy?

spaced out equally and symmetrical, if possible... It'll never be perfect unless you always grow clones. Growth patterns vary. Some will inevitalby fill their area of responsibility faster than others.. some wills tretch more... som will bush out more. Only with clones can you expect the same growth pattern from each and even then there is user-error. *equally spaced relative to useable space.. e.g. if you got fans ora dehum etc eating up some space and it's more like a 3x3 growing area, 4 would be great. 1.5'x1.5' is a fairly small plant. you won't need much of a vege phase for that. Most autoflowers could probably fit in that footprint, too. Really you only have to worry about when too many causes even a 12/12 from seed (minumum vege time) to be too large causing consistently overcrowded canopies. You could also drill for multiple patterns or do so in future... can always put a neoprene puck inside an unused hole.

In that area, I would only grow 2 plants...............6 is way too many...............4 would be the absolute maximum.

Let them grow for a good two weeks, and then decide depending on the plant, based on growth and phenotype. I would leave this decision up to the plants. 😀 good luke !

They all want the same space