You are 4 weeks from germination......not 4 weeks veg.
You could easily go for another 4 weeks of veg from what it looks like to me.

Hold your hand under the light. how close can you get before it is too hot when held there? If possible move your light almost that close to the plant to ensure tight internodes.

Wait five days and see where growth is before tying or bending again. Get an idea of the best direction to tie.

To give you an idea, I have had a plant (Mother) in veg for nearly 4 months and still continue to train the plants growth. It is only 16" tall but 12" round.

Keep the lights on a consistent cycle, water regularily and keep the temps manageable and you can veg as long as you want.

Hope that helps. BTW, you could take a clipping off each in 2 weeks and sex the plants that way rather than going 12/12 and reverting back which could take 2-3 weeks to get back to veg.

Anyway, have fun.