When to Ditch the Three-Act Structure?

Hey everyone, I'm working on a new script, a character-driven drama, and I’m finding myself wrestling with the traditional three-act structure. I've used it religiously on my previous projects, like my short film 'Echoes in the Rain,' and it’s always given me a solid backbone. But this current story feels... different. It's less about a clear inciting incident and more about a slow, evolving internal journey.

The industry guide I follow lays out the three-act standard beautifully, and touches on alternatives, but it doesn't really delve into when you should intentionally deviate. I've tried forcing a few 'plot points' into this story, and they just feel artificial, like I’m ticking boxes rather than letting the narrative breathe organically.

So, my real question is: under what specific story conditions should a writer consciously break from the three-act framework to genuinely serve their narrative better?