Not only are in-situ property systems that DO work likely to me “mixed”, I’ll offer as Poor Richard’s hypothesis the prediction that any future system with the slightest chance of working will also be mixed or eclectic.

re “the numerus clausus principle, which calls for constraining the menu of permissible property forms”

I see no reason we can’t have both a short menu and a long menu. There is utility in “chef’s favorites”, specials of the day, and a la carte alike. Casual owners may be well served by normative forms of ownership that are easily/cheaply defended in court. “Specialty owners” like a Land Trust or a worker-owned engineering coop may need more customized solutions.

Bravo! This goes to the problem of placing economics/politics/law on a more empirical, scientific, and self-correcting trajectory. I’m glad that more intellectuals are willing to study reality (in this case the history and anthropology of property law “on the ground” and “in the field”) as a starting point in their efforts towards reform and progress.

Arrangements worked out over centuries and millennia often embody strategies for resolving ambiguity and complexity that are themselves ambiguous and complex.

Too many well-meaning reformers fail to observe the “if it aint broke don’t fix it” rule and the “don’t throw the baby out with the bath water” rule. If we fail to properly correlate causes and effects, we often fix the wrong thing and/or produce unintended consequences (sometimes known as “shooting oneself in the foot”).

“…incentive misalignments that require attention…” Property law is probably as complex as a motorcycle, and fixing it is more like motorcycle mechanics than philosophy.

One thing I have learned about private vs community property: chain saws should be privately held. It only takes a instant to dull a chain whereas expert sharpening is non-trivial. The guy who messes up the chain should be the same guy that has to sharpen it and should be the only guy who gets hurt because of it.