@andy-dienes @Sass I think this conversation has gotten off track again.
In my opinion, one of the biggest problems we struggle with as a movement is siloing. The research and academia world is very, very out of touch with the advocacy landscape and the politics of reform, and vice versa.
Worse, the strategies of each branch of the electoral reform movement; general voting reform, PR specific voting reform, gerrymandering, the electoral college, election integrity, etc, are often super out of alignment with each other. In a lot of cases each of these 'factions' has a pitch and strategy that makes sense in a vacuum, but together, they don't play nice and are maybe even harmful to each other. In many cases, these factions are pretty oblivious about each other. (Which is where a forum like this could help.)
Obviously, most of the researchers you cite are very well informed in their specialty areas, but I wouldn't assume that an expert in parliamentary systems and List PR would be well versed in STAR Voting, cardinal voting, or in proposals that might be able to get some overlapping outcomes from a very different mechanism. I wouldn't assume that gerrymandering experts are well versed in campaign finance reform (CFR) or that CFR advocates are well versed in PR.
While academia is often good at getting the right answers, I'm not convinced that they are good at asking the right questions and I think have done a pretty bad job in many cases at looking at politics and reform holistically and understanding the various intersections.
In terms of political viability, I think it's important to look at the landscape and the impact of each reform on those who have the power to pass it. For example, the National Popular Vote Interstate Compact has passed in a lot of blue states but will have a harder time in red states because the electoral college benefits the Republican party. Until that changes this proposal is unlikely to pass and stick, regardless how much good it might do if it did.
Similarly, I think it's unlikely that a state where one party has gained an edge due to gerrymandering would pass a reform like PR that requires them to give up that edge. In a state like Wisconsin...
"Just look at what's happened in Wisconsin, where the state legislature has a supermajority with a minority of votes."
... I think it's unlikely that a faction that currently has a supermajority of seats and has an advantage from the existing system would pass a reform like PR that's specifically designed to ensure they give up that advantage. On the other hand, because they have a red supermajority they likely have a lot of vote-splitting within their fractured party, and might be more open minded to STAR, which would help, but wouldn't explicitly take away their power.
I'm in no way convinced that we should stop working on single-winner reform everywhere because PR could fix gerrymandering in places like Wisconsin. It may be politically viable and legal in some jurisdictions, but it's not legal or viable in the places that need it the most, at least not if voters actually understand the system and it's implications.
@Andy-Dienes, a lot of your posts rely very heavily on appealing to the opinions of authority figures in academia to convince us we are wrong in terms of our reform strategy. Then you link to 50 pages of articles without any indication to which points you think are persuasive or relevant. These articles make a ton of great points I agree with, but also raise multiple points that I find unpersuasive, that conflate causation with correlation, and that fail to control for other factors that absolutely are at play.
This isn't constructive and it doesn't set us up to find our specific points of agreement and check them off, or find our points of disagreement and discuss them. It sets us up to do what we've done in this thread, which is go all over the map arguing dozens of separate points at a superficial level while offending each other and then spending more time on the discussion than we'd intended.
If we want to get into the bigger picture we should start a new thread, but I think we should try and get back to talking about the number of candidates in a race, how different systems and mechanisms effect that, and what the ideal is.