>>2999531
Don't be so sure that they are video compression artifacts. Remember these are AI video gens, and there are all kinds of techniques involved in getting the generation time as low as possible; many of these come at a cost to quality. In my case, I am using the lightx2v lora (specifically the latest 2.1 version) which does have an effect on the final output.

Because this one >>2999489 is only 10 seconds, I can keep the bitrate relatively consistent with the original output's bitrate while still staying under the 4chan filesize limit. In cases like this Kyou webm, I have to lower the resolution and the bitrate because it's just a bit too long. I am encoding VP9 with 2-pass and maximum render quality.
Cutting the video to be shorter gives more potential for a higher quality video, but it kind of defeats the purpose of creating a longer video.