First, the whole post makes sense to me.The only implications from the marriage of those two above and your persistent action resolution harmony at your table is "prabe is a good 5e GM and his alchemy with his players works."
That is a statement that all GMs should hope for as a broad statement of their play. But using it as a proxy for "a 5e GM self-constraining via extra-game principles smuggled in so that they can limbo well under their mandate + action resolution procedures can reliably achieve table-synchronous action resolution across any four 5e players (who are not inherently dysfunctional or combative)" is extremely fraught.
But honestly, that is intentful design. That is a feature, not a bug. The designers willfully designed in heterogeneity across the population of all 5e tables; "Rulings not rules, natural language, make the game your own, and find your own alchemy." But it doesn't stand up that you can reverse engineer that design intent to say that your "found alchemy" is reproducible at scale because "competent GM + intentfully designed cross-table heterogeneity." I'm not saying you're saying that, but if that is the implication, it can't stand up. I'm sure there are stray anecdotes of relative "Edens of 5e Protagonistic Play" sprinkled about the "5e-osphere" (like yours). But if its happening at scale, (a) its happening quietly and (b) all of the noise that says it isn't is somehow just a flukily robust noise masquerading as signal. Further (and again), where the anecdotes do exist, there is a lot of "extra-synchronicity" stuff that are consequential aspects of that alchemy (when it comes to action resolution mediation specifically).
Man, that is a lot of crap I just wrote. I hope that makes sense.
Second, My point has been that the kind of 5E play that happens at the tables I'm DMing is possible, and I know it's possible because I see it happen. I agree that it's difficult-shading-to-impossible to reproduce what you aptly describe as "table alchemy" at anything like scale; I suspect part of the (intentional) design of 5E is to encourage that (cynical interpretation: so that two tables playing the same AP feel different).
Third, I think I'm a better 5E DM for having run other games. Most of the "extra-game principles" you mention probably have come from that, with some amount coming from both positive ("do that") and negative ("for the love of all that's holy don't do that") examples from the relatively small number of GMs I've played with.