I doubt that it is auto up votes that are the real issue. Look back and see what post were first down voted, most likely a Covid 19 pro or anti post. It seems that most down votes these days are from people and trails that do not like the message that is being posted about. Flat-earth=downvote/covid=down vote/religion of any type=down vote/political affiliation=down vote.
If there were no down vote trails then there would be fewer down votes based on ideology, but people wanted all the youtube stars, and other influencers, and this is what we got, masked people behind names down voting ideology.
I only vote on some of your stuff and that is things that apolymask see and finds interesting, or other of my followers find interesting and re-blogs your post.
Auto up vote trails are needed for several reason most of which you covered in your post. It takes time to find post that I want to vote on, I can not imagine what is going to happen when I have a much larger vote, post I vote on being down voted because I was to generous in my vote? I am not there yet but hope to be someday.
RE: How Many Of My Upvoters Are Actively Using Hive? (Addressing Downvote Cancel Culture on Hive)