• [varLib] Clear USE_MY_METRICS component flags when inconsistent across masters (#3912).
• [varLib.instancer] Avoid negative advance width/height values when instatiating HVAR/VVAR, (unlikely in well-behaved fonts) (#3918).
• [subset] Fix shaping behaviour when pruning empty mark sets (#3915, harfbuzz/harfbuzz#5499).
• [cu2qu] Fixed dot() product of perpendicular vectors not always returning exactly 0.0 in all Python implementations (#3911)
• [varLib.instancer] Implemented fully-instantiating avar2 fonts (#3909).
• [feaLib] Allow float values in VariableScalar's axis locations (#3906, #3907).
• [cu2qu] Handle special case in calc_intersect for degenerate cubic curves where 3 to 4 control points are equal (#3904).