Nintendo Maniac 64
I made SVP31-script by your picture. See file attached.
Difference is present in 7 places:
1. SVP4 uses 3 threads instead of 7. It is not critical but can lead to jerky playback.
2. SVP4 don't use GPU-acceleration (gpu:0). It can give more artifacts at frame borders and overall.
3. SVP4 uses 28px vector grid instead of 16px. It must give less artifatcs but less smothness.
4. SVP4 uses Average wide search (bad.sad:1000 by default) intead of Strongest wide search (bad:{sad:2000}}). It can give less smoothness of small objects.
5. SVP4 uses Sharp shader for anime (algo:2) instead of Standard shader (algo:13). It gives more visible artfacts around moving objects.
6. SVP4 uses Repeat frame on scene changes (blend:false by default) instead of Blend ajacent frames (blend:true). It can give more jerky playback at fast scenes and at scene changes.
7. SVP4 uses adaptive frame interpolation mode (mode:3 by default) indtead of "1m" mode (mode:1). It gives more smoothness but more artifacts.
So, I see 3 causes wich can lead to more visible artifacts: #2, 5 and 7.
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BTW, My lower-end CPU (mobile i3-3217U) gives me more smooth playback and less artifacts with SVP4 and with profile settings by default than if I use SVP 3.1 with your settings.