Since 63.1 was a hotfix, it carries over the major improvements introduced just days prior in version 63.0:
: Resolved an issue that blocked the saving or updating of Cloud documents when working in a shared team environment. Sketch 63.1
: This version requires macOS High Sierra (10.13.4) or newer. Since 63
: Made selection behavior more consistent, specifically when Shift-dragging over points. Since 63.1 was a hotfix
: Significant performance boosts for sharing complex documents with teams.