I agree that activism in particular has a lot of idiosyncrasies, even within the broader field of systems change, that make it harder to model or understand but do not invalidate its worth. I think that it is worthwhile to attempt to better understand the realms of activism or systems change in general, and to do so, EA methodology would need to be comfortable engaging in much looser expected value calculations than it normally does. Particularly, I think a separate system from ITN may be preferable for this context, because "scope, neglectedness, and tractability" may be less useful for the purpose of deciding what kind of activism to do than other concepts like "momentum, potential scope, likely impact of a movement at maximum scope and likely impact at minimum or median scope/success, personal skill/knowledge fit, personal belief alignment" etc.

I think it's worth attempting to do these sorts of napkin calculations and invent frameworks for things in the category of "things that don't usually meet the minimum quantifiability bar for EA" as a thought exercise to clarify one's beliefs if nothing else, but besides, regardless of whether moderately rigorous investigation endorses the efficacy of various systems change mechanisms or not, it seems straightforwardly good to develop tools that help those interested in systems change to maximize their positive impact. Even if the EA movement itself remained less focused on systems change, I think people in EA are capable of producing accurate and insightful literature/research on the huge and extremely important fields of public policy and social change, and those contributions may be taken up by other groups, hopefully raising the sanity waterline on the meta-decision of which movements to invest time and effort into. After all, there are literally millions of activist groups and systems-change-focused movements out there, and developing tools to make sense out of that primordial muck could aid many people in their search to engage with the most impactful and fulfilling movements possible.

We may never know whether highly-quantifiable non-systems change interventions or harder-to-quantify systems change interventions are more effective, but it seems possible that to develop an effectiveness methodology for both spheres is better than to restrict one's contributions to one. For example, spreading good ideas in the other sphere may boost the general influence of a group's set of ideals and methodologies, and also provide benefits in the form of cross-pollination from advances in the other sphere. If EA maximizes for peak highly-quantifiable action, ought there to be a subgroup that maximizes for peak implementation of "everything that doesn't make the typical minimum quantifiability bar for EA"?

I agree that to the extent that EA engages in policy evaluation or political/economic evaluation more generally, it should use a sentient-experience maximization framework, while discarding the labels of particular political theories, in the way that you described. And I think that so far every discussion I've seen of those matters in EA follows that framework, which is great.

With regard to specific arguments about post-politics:

I thought you made a strong case for post-politics in general, but arguing that a specific economic strategy is the best possible beyond all doubt is much more difficult to defend, and besides, does not seem very post-political. In general, a post-political person might argue for any economic strategy under the sun as optimal for sentient beings, though of course some arguments will be stronger than others.

Also, regardless of the systems they believe to be optimal, post-political people should be sure to entertain the possibility that they, others, or a given group or polity are actually too post-political--not having the optimal amount or type of cultural orthodoxy/dogma and being unwilling to address that issue.

This may come into play when an individual or group's conviction in rights and other deontological tools becomes too weak, or the deontological rules and norms they follow are worse than competing options.

After all, an orthodoxy or political culture beyond post-politics is necessary for "tie-breaking" or producing decisions in situations where calculation is inconclusive. Some political culture beyond post-politics will inevitably sway people in such situations, and it is worth making sure that that political culture is a good one.

An individual post-political thinker therefore may embrace advocacy of a certain political culture because they think it is so valuable and under-utilized that advocating for it is a more efficient use of their resources than advocating for post-politics.

Generally I would say most people and institutions could stand to be more post-political, but I am not sure whether post-politics is currently a better advocacy target than other cultural/political movements.

If one was to advocate for such a movement, I'd guess the best way would be to create a political forum based on those principles and try to attract the people who like participating in political forums. Then the goal would be to make sure the discourse is focused on doing the most good for the most people, with rigorous evidence-based breakdowns for particular policies. This might be a decent use of time given that this post-political approach could improve thousands of people's decisions as they relate to systems change.

If something like this was created, I would recommend adding a system for users to catalogue, quantify, and compare their political positions, including their degree of confidence in each position. The capability to quickly and easily compare political positions between individuals seems like a very fast way to advance the accuracy of individuals' beliefs, especially in a community dedicated to strong beliefs lightly held and finding the policies that do the most good.