All of them look ready for transplant into larger containers. What size container do you plan to flower them in? That could be holding them back from growing quicker. Also, what grow light are you using and how far away is it from the top of the plants?
@michaelherndon.21 They all look like they would have a big enough root structure. You can flip to a flowering light cycle whenever you want. Most growers will fill up their grow space while other growers don't worry much about yield and will flip before the grow space is full. Your choice.
All of them look ready for transplant into larger containers. What size container do you plan to flower them in? That could be holding them back from growing quicker. Also, what grow light are you using and how far away is it from the top of the plants?