I'm not the person you asked and I don't have any particular knowledge of postgres internals. Experience with other systems has taught me that in a system that

I'm not the person you asked and I don't have any particular knowledge of postgres internals. Experience with other systems has taught me that in a system that's been in active use and development for decades, entanglement will be deep, subtle, and pervasive. If this isn't true of postgres then it's an absolute freak anomaly of a codebase. It is that in other ways, so it's possible. But the article mentions there being thousands of global variables. And Tom Lane himself says he considers it untenable for exactly this reason. That's a very good reason to think that it will require that many changes imo.