In my case, only the lady who helped check the application forms asked if I had changed to F1 when she looked at my DS156 form, I said yes.
All the VOs in Toronto are very nice. my VO asked me two simple questions: where do I work and what is my Major. only document I shown to him is my employer's letter.
so do not worry to much. I do not believe you can fail just because you are B-F-H.