• Dropped support for EOL Python 3.6, require Python 3.7 (#2417).
• [ufoLib/glifLib] Make filename-clash checks faster by using a set instead of a list (#2422).
• [subset] Don't crash if optional ClipList and LayerList are None (empty) (#2424, 2439).
• [OT-SVG] Removed support for old deprecated version 1 and embedded color palettes, which were never officially part of the OpenType SVG spec. Upon compile, reuse offsets to SVG documents that are identical (#2430).
• [feaLib] Added support for Variable Feature File syntax. This is experimental and subject to change until it is finalized in the Adobe FEA spec (#2432).
• [unicodedata] Update Scripts/ScriptExtensions/Blocks to UnicodeData 14.0 (#2437).