The latest patch still doesn't fully auto play the demon fights. It instead never auto rerolls for you but does pick targets for incoming damage.
Yup, I guess it does get pretty ridiculous. And made even worse by your large amount of damage dice boosts. But I don't really know what the best options would be for these. Obviously they need to keep getting harder as I think they're the main reason the runs actually end. What fun would it be to play forever without it getting any harder?