How many colas can I fit in a 2ftx2ft before crowding becomes an issue?

To me it makes no sense to do 2 plants or 6 plants or whatever. You do 1 or you do 4.. Keep it symmetrical. That’s said, I’d be doing it plant if you’re gonna main line you’re taking time to veg and 1 plant will fill up a 2x2 if mainlined - shoot for 16-24 tops.. usually lower growth you can top an extra time, giving you some extra tops. If you’re gonna push more than 16 you better have environmentals on point, cuz you’re gonna have a lot going on in a small spot and can get WPM and humidity issues.. I’d go one plant 16 tops. You’ll be able to flip after 6-8 weeks if you grow decently. Good luck