What would happen if I tied my hair up or wore clips after my Brazilian blowdry?

Just had my first Brazilian blow-dry (excitement) but I am going mental with my hair hanging like a shower curtain in my face. (It's itchy and getting in the way of cooking etc) Why do the hairdressers advice that you should not tie your hair back after a BB? Would it form a permanent kink in the place I wore the scuncy/hairband/hair-clip? I had the treatment done to control my frizz and I don't really care if I develop a mild kink. Would wearing it tied back loosely with a scuncy while Im cooking etc be fine as long as I pull the straightening irons though my hair afterwards?