From the release 1.4, plugin supports HTML::Mason framework:

• Parsing of HTML::Mason files
• Configuration for autohandler and dhandler names, component roots, global variables, component file extensions and custom tags
• Autocompletion and highlighting of syntax elements
• Proper component variables resolution according to the compiled component structure
• Components hierarchy resolving
• Subcomponents and methods resolving from Mason invocations
• Navigation, completion and refactoring for components, methods and subcomponents
• Configurable templating language

Since version 2018.3 HTML::Mason support available via separate plugin.