A user says that a custom keyboard layout for a RTL script behaves as though it were LTR in Sonoma. In looking into it, I see that there is a new look to the Input Sources section of System Settings, with a section that only appears for RTL scripts.
At a guess, this indicates that there is a new key for the Info.plist in a keyboard layout bundle, probably to be under the KLInfo_*** for the keyboard layout. These never seem to be documented, but people stumble on them occasionally. Is this another case? Has anyone seen such a key, or is there something else going on?
