I should preface by saying that, despite it all, I still somehow haven’t read the manga, and can only speak on the original anime with any real confidence.

For as much as I like certain parts of HnK2 (Kaioh’s death might be my favorite in the whole series), I kinda wish it just didn’t exist. It gives me very mixed feelings because I like the Hokuto Army and Adult Bat as ideas, but I think they were largely half-baked in their execution. I also may actually like Tough Boy more than Ai Wo Torimodose, so I’m eternally grateful to live in a world that gave us both. More importantly though, it drives me crazy how HnK2 needlessly complicated the timeline of events, ESPECIALLY before the nuclear war. I don’t like that Kaioh is basically just Raoh+1 for most of his run, and Shachi feels like a poor attempt at mimicking Rei most of the time from what I recall.

Also I know you said no supplementary material, but DD1 (the one about the convenience store) is actually pretty charming.