• [feaLib/otlLib] Moved lookup subtable builders from feaLib to otlLib; refactored some common code (#2004, #2007).
• [docs] Document otlLib module (#2009).
• [glifLib] Fixed bug with some UFO .glif filenames clashing on case-insensitive filesystems (#2001, #2002).
• [colorLib] Updated COLRv1 implementation following changes in the draft spec (#2008, googlefonts/colr-gradients-spec#24).