Lower humidity should make the problem worse because the dry air is sucking out the moisture so sure, higher humidity could help. I think around 40% is typically where my main room hovers - but it's not like I don't still have funky leaf curl stuff happen from time to time too. Also, once you have bigger pots and plants and more moist soil and such in an enclosed area your humidity should increase some.
Usually when I see minor issues like your small amount of leaf curl I kinda look to all the basics and just try to be sure I'm doing things right. I try not to make big reactions. Hopefully they'll grow fine after the pot-up - I think it was the right move. If the curling does continue, it will be much easier for you to evaluate and adjust the watering with a slightly larger container.
I can't tell what all you have there, but I see some MOA bonnets. Are you posting grow pics in another thread? I thought I'd seen you post about your grow elsewhere, but I just finished a long work day and can't remember ATM. It would be cool to see more about your grow and pics of them after pot-up.
Good luck!