Supercrop if need be!
You're lucky it's so early on,
You can very well tie the plant down, some people even super crop at the early stages of flower.
But if you want to take it easy, yes just get some garden wire or soft string and tie those bad girls down to the pot !
You can do it when you want - need. Later bloom is OK too!
manifolding/mainlining is your friend.
"Mainlining" is best done from the time the plants are topped and have several "mains" starting. You tie them down and train them to grow up once they have been spread out..(as far as you like)...This can be done after multiple toppings.
Starting to "tie down" at this point is
not mainlining in my book!
Before you start the next run. Put something white (flat white) on those walls. Get the light working for you (reflected). You could use a mirrored film if you like - You would have to attach it at the edges only and run a fan in there!
I see your growing in some "buckets"? At least 1, 5 gallon bucket! I don't see any holes in the bucket for drainage/aeration ! That is a "bad" thing!
Plastic pots made for growing are easy to get and cheap if know where to look! Take a look at Plant Warrior pots - good stuff!
Skip the "smart" pots....
Good luck