Anything Goes : The audition process by Ashoka Chowta

I would say no unless the writer is also a producer, in which case, you may not have a choice. In the audition process, the choices of who portrays each role should be left to the director and the producer. Two many cooks spoil the stew. The writer has modeled each character in their head and has definite ideas as to how each should be portrayed, but he is not directing. Save yourself some trouble and only call the writer for the table read and on set rewrites. Sorry writers.

NO

And that is why you don't want writers at auditions or on set.