Does Moodle maintain consistent focus management in legacy plugin modal dialogs?

Focus Management in Modal Dialogs

Moodle aims for WCAG 2.1 Level AA compliance by utilizing ARIA landmarks and labels to support assistive technologies. While the core 'Boost' theme implements standardized accessibility patterns, the behavior of modal dialogs can vary when triggered by legacy plugins.

A critical requirement for keyboard accessibility is the ability to trap focus within a modal window until it is dismissed, preventing the user from accidentally interacting with the background page. There is uncertainty regarding whether these legacy components adhere to the current focus management standards used in the core codebase.

What is the expected behavior for focus restoration when a legacy plugin modal is closed? Does Moodle provide a standardized mechanism to ensure focus returns to the triggering element across all plugin types?