Correcting myself, > AFAIK, PRIORITY never was intended to be inherited. Inheritance applies > to node properties, i.e. property drawers, whereas special properties, > like PRIORITY are, by definition, not set through property drawers.
This is incorrect. What I mean is inheritance is not automatic for special properties, unlike to regular node properties. In any case, this doesn't depend on `org-use-property-inheritance'. Few of the special properties are inherited, e.g., BLOCKED, and /always/ are, most are never inherited, e.g. ITEM. > There is also a technical issue: Org defines a default priority, so > PRIORITY is never empty. Again, inheritance kicks in when a property is > undefined at some level. This never happens in this case. We need to redefine `org-default-prority' to solve this, e.g., the variable only applies to top-level items.
