The producer certainly dictates the style and size of the plants. Does each plant have about 9x9" grow space? To grow in that space the plants can not veg for very long and would have to be severely restricted as to their size and shape. There are several posts about growing in solo cups or net pots. What they have in common is numerous plants, short veg, and pruned to only a few colas. Search solo cup challenge, Sea of Green SOG.
I am nearing the end of a SOG grow of six plants, in 1-gallon pots, coco & Jack’s is a 2x2 scrog frame Another Clone SOG and TBD
Before that I did 12 single colas plants in 6" nursery pots in soil in the same frame.
17 - 18 plants can be done in that space but it will require major pruning and maintenance. You mentioned numerous pinching. Are you talking about topping or pinching off growth tips? The latter would be the necessary action.
You can see from my referenced thread I am a fan of combining the two methods. SOG with SCROG.
Just some thoughts. Good Luck.