- When an undocumented parameter is unchecked, its outline element should remain for that edit session only. If the template is saved while it's unchecked, then re-opened its outline element should be gone.
- Focus changes in the same way as documented parameters when checked/unchecked.
- Add a message next to the label "(Undocumented parameter)" 13px, Base30, italic.
Related: the input for undocumented parameter is done in T272487: New input for undocumented parameters