Kagi appears to be injecting an YoutubeADB script that makes pausing videos before the first second impossible. This happens even with content blockers, etc. disabled.
From inspector, inside a kagi.ytab function I see:
/**
* 自动播放
* @return {undefined}
*/
function playAfterAd(){
if(video.paused && video.currentTime<1){
video.play();
log(`自动播放视频`);
}
}

Attempt to pause video / rewind video to zero seconds. I expect the video to stay paused, in other browsers it does, but in kagi it autoplays, even if I attempt to pause.
0.99.131-beta
Sequoia (15)