HarfBuzz 12.3.0 is out, faster than ever:

- AAT shaping: 12% faster, LucidaGrande benchmark.
- OpenType shaping: 20% faster, NotoNastaliqUrdu benchmark.
- Drawing mega variable-fonts: 30% faster, GoogleSansFlex benchmark.
- Drawing VARC fonts: 5% faster, varc-hanzi benchmark.

https://github.com/harfbuzz/harfbuzz/releases/tag/12.3.0