I don't think you can control the density/amount of rain that comes down without Cinematic Tools.
I think some weather effects were changed from the Alpha/Beta for better FPS (At least thats what I heard)
Expect some extra enhancements during post-production for the trailers..
Although you can try playing on 200% resolution scale and see how it goes.
There also could be a difference if you're playing on 1080p. Should look way better on 1440p/4K
https://www.youtube.com/watch?v=L-klt1u_7RM&ab_channel=TheFrostbiteProject
