Emacs Core and OS Accessibility Bridge: Overlay Communication

Emacs provides an internal accessibility mode designed to translate buffer states into standard UI elements for operating system accessibility APIs. This integration allows screen readers to track the point and regions within a GUI session.

However, a gap exists regarding how the accessibility bridge handles custom-drawn overlays and non-standard fringes. While standard text mutation is communicated, elements rendered via overlays often bypass the standard buffer mechanisms used by the OS-level accessibility tree.

When implementing custom UI enhancements in Elisp, it is unclear how to ensure these visual markers are exposed to assistive technologies without sacrificing performance or introducing latency in the accessibility tree updates.

• How can custom overlays be mapped to the OS accessibility API to ensure they are announced by screen readers?
• What is the recommended method for triggering immediate accessibility tree updates during rapid text mutation in GUI Emacs?