I started working on #LibreOffice again, two new developments:

It now instances variable fonts when embedding in PDF instead of drawing the outlines as PDF vectors (using PDF Type 3 fonts), which is more efficient and allows the text to be rendered as fonts not graphics.

This uses #HarfBuzz subsetter under the hood, so while at it, I replaced most of LibreOffice’s ancient (CVE-happy) low-level font subsetting code, with HarfBuzz subsetter.

CFF2 fonts are still drawn as graphics, but next of version of HarfBuzz will support downgrading CFF2 to CFF after instancing, and I plan to use that when it is available.

> CFF2 fonts are still drawn as graphics, but next of version of HarfBuzz will support downgrading CFF2 to CFF after instancing, and I plan to use that when it is available.

#LibreOffice now uses the new support in #HarfBuzz 13.0.0 for downgrading CFF2 table to CFF when instancing variable fonts with CFF2 table.

CFF table is still concerted to Type 1 fonts by LibreOffice when embedding such fonts in PDF. Making it embed CFF table directly is left for another day...