@aardrian Semi-sweet -- I was partly misremembering now I come back to look at the test page I made. They're both fine in iOS/VO (but don't support role-description), whereas neither are announced in macOS/VO (unless they have a role-description and are focused).

This is the test page: https://cdpn.io/pen/debug/YPzgYVM

This is the application (uses `<mark>` and `<del>` with role-description and interactivity): https://cdpn.io/pen/debug/OJeqBZm

@matuzo