I'm willing to negotiate in most cases, as long as it makes sense. For instance, if you decided you really wanted Snow White to take a dominant role, we could talk that out. Or if you wanted to move a historical plot into modern day, that, too, could be discussed. Some, however, I'm set on, ex: Hippolyta in Chains really requires a sub female role, even though I have been asked to make her dominant.
Also, if you have elements you like, I can write a custom plot for that.