That depends on what "beneficial" means. Getting an A out of the darkness and into the light is always the best policy. Ultimatums are always a risk. I've seen them given here and the other spouse walks. I've seen them work. It worked for me. I just said I won't be married to someone having an A and I filed for divorce. That did the trick in my case and snapped her out of her funk. She realized she still loved me more than she didn't. The thing is, that can go the other way too. They may realize they don't love you anymore. You have to be emotionally prepared for either outcome. That's why detaching is so important. If you follow the guidelines and truly detach (don't fake it, do it) then you create a no-lose situation for yourself. She either goes all-in on the marriage or you get a divorce but either way you move on healthy. The only way to lose, honestly, is to remain in limbo. Limbo is soul sucking and isn't healthy for anyone.
