perm comb out

I have an appt. 3/10 to have a "perm combout" applied to my hair, and I'm thinking about canceling it after reading all the horror stories about straightening hair. I spoke with a stylist who did a strand test. She said she thinks it will work on my hair, but because she could not blow dry the strand test (she cut a piece of my hair), she wasn't sure if it would frizz up. I had originally asked her about the Redken curl reducer, which my sister had done and was happy with, but because my hair is highlighted she said that was not a good idea. My hair is past my shoulders, very wavy and coarse, and very very thick. Has anyone ever had this done or know anything about it? Thanks for any info you can give me.