I've done several experiments with LL-HLS and what I've noticed, is that when I load a master m3u8 playlist that Safari (14.1.1 MacOS) always downloads the oldest EXT-X-PART and not the newest which are closest to the edge.
Why is that? If low-latency is one of the goals of LL-HLS, shouldn't the player, e.g. Safari start loading the EXT-X-PART which is the newest one?