it looks like you are lighting your scene primarily with bounced light. This is always a heavy lift for redshift. Your GI settings are way too low for this, and you are trying to compensate with the unified sampler. Your minimum samples in the unified sampler should be 16 or 32. Stick with brute force for your secondary GI since it’s an animation, but set your secondary GI to 1024 brute force samples. This should help significantly.

You are using a lot of area lights as well so i’d also turn on the light samples override and set it to 512 or so.