Filtering->Speed Change will trigger the use of those.
For actual frame chagnes, instead of those, I would recommend using the the filters under Avisynth->Frame or better Vapoursynth->Frame.
(I don't really use Avisynth anymore)
For actual frame chagnes, instead of those, I would recommend using the the filters under Avisynth->Frame or better Vapoursynth->Frame.
(I don't really use Avisynth anymore)