Looks mostly good. I think it's similar to my settings before I started using RIFE, but honestly I don't remember them exactly as it has been a long time. RIFE through SVP, is a huge upgrade over traditional SVP, but if you watch 4K content at 4K, then I don't think the 2080 is strong enough, I have a 3090 and it's barely enough.
Consider changing Motion Vectors Grid to 28 or 32, the larger it is, the less visible artifacts from what I remember.
Motion vectors precision to One pixel, instead of half.
Artifact masking to 400 instead of 200 (strong is 200, strongest is 1000). Check the image below for how to do that, scroll down all the way until you find your TITLE name there, then go up to fi_masking and change it from 200 to custom value.
Strongest (1000) causes smoothness issues from what I remember, but between 400 and 700 was a great testing place for me.
I've done some testing and i find these settings to be the better for my use case
Frame interpolations: Adaptive (uniform - 1m - 2m)
Custom artifcat masking at 550
Changed vector precision to one pixel
and motion vector grid to 28
And rest is essentially your settings. Which works really well for my use.
I've tried using Rife Engine but yea, 2080 is barely enough for 1080p let alone 4k content from my testing.
Now ofcourse, if anyone else has more recommendations to try out i'd welcome it.