
We have 34 plants spaced approximately 2 feet apart. Admittedly, it is a bit more of a jungle than we would prefer and pruning would certainly help with that but the additional gardening chore isn’t appealing for the convenience of more space to maneuver. Utilizing a Florida weave would help create more space for those short on it. Space isn’t much of an issue for us, if we need more I’d rip up more lawn without a second thought. It is dense this year because we are running 4 varieties…so we have 4 rows.
We’ve never weighed out the production from our plants because we always have more tomatoes than we have time to eat/process/preserve. I imagine if pruning increased yields we’d see more of it from market gardeners and the like, but I’ve never seen it — there would be a labor/time trade off there as well.
If space is a concern you may want to consider a keyhole design for laying out your gardens. The design is widely considered one of the most productive per square foot, as it minimizes requirements for foot paths.