Hello 
It’s possible to disable it in composer with changing the AI helper features with a site setting.
ai helper enabled features
By default it contains: suggestions, context menu
Suggestions is what makes possible to generates title, category, tag etc.. to the topic.
Context menu is I guess what you want to disable in composer.
So if you remove context menu from the selected then it won’t available in composer but the [Ask AI] will still visible on posts.
Sorry if I misunderstood your request…