Hi Vince!! Thanks
Regarding your question, I always use UHD Cache Animation and I almost working with 4% of noise limite plus full Corona Denoising High Quality.
But when I get more reflections/refractions I change the Max Ray Depth from 25 to 30 or more depending how much detail I want. But increasing the Ray Depth will increase the rendering time.
Sometimes I need to denoise/deflicker in post some moving object using matted element.
The avarage time depends on each scene. A fast scene with a lot of alpha area takes about 2min up, but a full scene with SSS like the fried Characters took 10~15min
My computer is an AMD Ryzen 9 3900X, 64GB Ram and RTX 2080 Ti
I also do a lot os compositing on After Effects to make fine adjustments