The current special case accessors are inconsistently named and inconsistently implemented in the Koha::CirculationRules module.. it would be better to allow access to rules via get_effective_rule and get_effective_rules consistently and remove the special accessors by replacing the special case handling, mostly adding defaults, with overloaded an overloaded value field accessor in the Koha::CirculationRule result object.
https://metacpan.org/pod/DBIx::Class::Manual::Cookbook#Wrapping/overloading-a-column-accessor
Is this still valid?