Fluid video masking at strongest & How is this interpolation possible?

First question: Setting artifact masking to strongest does seem to effectively take away most noticeable artifacts from interpolation, however it defeats the point by losing smoothness. I am just curious if anyone has a tweak to have it set to strongest, but still have the smoothness of it being disabled.

My second question is this: So I have noticed there are a number of interpolation video's on the internet that seem to show a level of software accomplishment that I didnt know could be done with interpolation. One such example is this video that takes a source video of 30fps, and effectively makes it 320fps with no visible artifacts or obvious evidence of interpolation. https://www.youtube.com/watch?v=Zz63hmavcMY

Having ran the original 30hz source video through SVP player, I was not able to accomplish anywhere near a convincing result as that. So how do people do this? Im sorry in advance if anyone finds this footage upsetting, however I have not found out how people are making it, and my previous attempts at finding an answer have not been a success, so I hope this forum can answer this.