I just retested in version 24w45a, and the empty slot outlines in the brewing stand and mount GUIs now appear between slot_highlight_back.png and slot_highlight_front.png. However, the highlight effect for empty slot outlines in the smithing table and loom GUIs seems unchanged.
Star_02048
I just retested in version 24w45a, and the empty slot outlines in the brewing stand and mount GUIs now appear between slot_highlight_back.png and slot_highlight_front.png. However, the highlight effect for empty slot outlines in the smithing table and loom GUIs seems unchanged.