The three attrs LibreOffice's Format… dialog is mostly about, on both
sides of the bar. They live together on one TextStyle mark and a mark of
one type replaces that type whole, so each run's own attrs are the base of
the new one — recolouring leaves the font alone.
F3 was bound twice from here on: it now expands an AutoText shortcut where
the caret has one, as it does in both word processors, and finds the next
match otherwise.
The ¶ toggle adds a format to each side: bold / italic / underline and a
paragraph style, as LibreOffice's Format… and its Paragraph Styles box.
A format narrows a text search to the runs carrying it, and with no term
the formatting is the search — every such run, or every paragraph in the
style, empty ones included.
A replacement with no text only reformats, which is how a document gets
restyled without retyping it; a heading style switches the node type over
the way setParagraphStyle does, so the extension takes the same sheet.
Steffen Becker