The input box border now displays a mode indicator tag (e.g. the model name and /fast toggle state) inline in the top-right corner of the border, replacing the previous approach. This is rendered by the new OZ5 component.
Evidence
New border tag component (search for fastModeTag in the OZ5 function at line ~629655)
Strings lifted out of the shipped bundle, so the claim above can be checked against them.