Follow up for T6046, from https://dev.gnupg.org/T6046#161722:
There is no accessible feedback when checking/unchecking user ID
This is caused by a bug in Qt which doesn't report the checkable state to AT-SPI.
Edit 2025-07-22:
The bug still exists in KF6 afaik.
To make things clear for testers, those are the check marks where you currently get no feedback by screen readers when you check or uncheck them: