Split Stock and When to Start 12/12

These two plants are grown in a 3x4x6 tent with two 300W LEDs.

These guys are pretty long into vegging. I messed a lot up at the beginning of the grow, and it really slowed them down. I think they're around 11 weeks. But they look nice and healthy now. The issue is the one on the left has a split in the stalk, fairly far down in a thick section. I saw it today while watering. It looks pretty recent. Not sure if the LST did it. I duct taped the stem together like a couple places said to do. So should I let it try to heal for a little while, then flip to 12/12? Or should I just go to 12/12 now? I don't want them to get much bigger as I know they'll explode once under 12/12 and I fear I may be short on room.

You can flip them now wouldn't be a big deal.

I agree with krypto, doesnt matter flip to 12/12 if your ready, those look small for 11 weeks though in my opinion, here is a pic of mine tonite and they are about 45days old from seed so almost 7 weeks

Yes, they are small for their age. I had some set-backs at the beginning and stunted the growth. Here they are in their home. They look like they are abutting the sides of the tent now. So flip to 12/12 sounds like the way to go. The plant seems fine a couple of days after the stalk split.