Mixin default argument change in Pug affecting template inheritance

Examining how Pug mixin default argument alterations influence conditional rendering behavior when mixins are invoked inside extends/block inheritance structures. The goal is to determine whether the presence or absence of a default value in a mixin parameter changes the boolean coercion outcome of surrounding if/unless blocks, and how child template redefinitions of block content interact with the mixin's evaluated result. Constraints include Pug version-specific handling of default arguments in mixin calls, the scope of parameter defaults across template boundaries, and the extent to which conditional expressions reference mixin-injected data. Uncertainty remains regarding whether Pug normalizes undefined default values uniformly across 2.x and 3.x releases when mixins are nested inside conditional blocks within inherited template hierarchies.

Does omitting a default argument in a Pug mixin parameter cause the enclosing if block to render its alternative branch in all Pug supported versions?

When a child template redefines a block that calls a mixin with a default argument, does the parent template's conditional take precedence over the mixin's resolved value?

How does the boolean evaluation of a mixin call with a default false differ from a call with no default within unless blocks under layout inheritance?