When does 'character' trump 'clinical' in documentary lensing?

Hey fellow filmmakers, I'm working on a doc right now about a reclusive artist, shooting on an FX3, and have been obsessing over getting the crispest image possible. I recently consulted a guide that cautioned against always prioritizing maximum sharpness, suggesting a 'character' lens might be more effective in certain narrative scenarios.

This really got me thinking. I'm usually chasing that clean, detailed look with my Sigma 18-35mm Art. But when would a softer rendering, or even pleasing flares, actually serve the story better? We're exploring the artist's fragile mental state and the nostalgic quality of their work.

Beyond simply 'a dream sequence,' are there any specific narrative scenarios (maybe exploring memory, emotional states, or subjective viewpoints) where you've found a less 'technically perfect' lens to be a more powerful storytelling tool? What have you tried, and what were the effects?