ACT Transfer Student Question

I am an incoming student at UNC Honors as an OOS student, but in case I don't like it there, I am still interested in transferring as a freshman (particularly Vanderbilt). Is it a good idea for me to retake the ACT (I currently have a 32) or can I go test optional and they will assume I have a good test score if I got into UNC Honors OOS? Please help.