The instructions are to flatiron every piece 10 (!) times.
I'm scared of heat damage so I asked my stylist to half that. I'm not sure if that makes it less straight but I'm assuming so.
After everything is done my hair is stick straight because she blows it dry, but as soon as I wash it again (which is usually the next day) my curls come back, only looser. And, apparently, stronger. My hair is very fine so retention is usually an issue but with the BB I don't have to manipulate my hair as much, which I am sure adds to my retention. I love it and even when the BB is supposed to be gone my hair is still strong!
And getting longer and longer and longer....
I haven't seen any videos of people having a keratin treatment enjoying their new looser curls but I'm sure they're out there......