I haven't done this myself, but I did see a film a few weeks ago that used anamorphic lenses for 1:1.85 delivery.
And my impression was that it didn't help the film at all. Just looked like good photography using bad leneses. It is a pain in the neck to film this way, so I'd suggest testing this idea fully before committing to this workflow.
In the film era we gained a lot of image quality exposing a larger negative with anamorphic lenses. With an Alexa, not so much, and the lens characteristics might become more of a distraction than an enhancement.
I will say this: the director was very proud of his DP's "original" approach, and so the marketing points here are real, in this competitive business
Good luck with the shoot, and make a great film, above all else!