Yeah I'm all about getting my numbers up for the space I have. I especially wanted to get every last JS seed I had represented in this run. I'd be heartbroken if I lost it... but I don't think I'll have much worry about it now. It's going to be an IBL in my collection for a long time, I have a feeling.
But yea, I've found that most strains are able to adapt. I give them about 18" square space. This run I used 0.5gal pots with coco, but I'm moving to 0.75gal which seems to be about where I'll settle (1gal was more than I needed). Depending on the strain and how long I veg, they'll still easily hit 3-4 feet but without the lateral sprawl. Everything crunches in, so I just keep up with trimming and canopy management. I don't usually top. I just supercrop the main down to the height of the next 4 nodes, and clear out as much as possible below the top ~1ft of canopy.