Key frame setting

Great work! (1)I would like to ask why the key frame test in the paper is 1,4,16,50 instead of within 10, such as 1,2,3,4,5..... Is this selection rigorous? Because I think the keyframe too far will lack the correlation between frames. (2)Is your work similar to six-plane factorization combined with tensor factorization like Hexplane?Doesn't count as a six-plane projection?