See, by you saying your W only knows her own way of doing things you are still fearful of her reaction.
I do not feel that way. I am not concerned how my W handles me now agreeing with her on divorce being the answer for the very reasons you stated. I am concerned about her being childish enough to make the divorce process more difficult than it has to be. I know I can't control that but I can maintain civility.
Don't make any assumptions for any of her actions, you don't know if she's going to be childish, adult, mature, civil, angry, etc.