Mesh vertex and face normals have been refactored, reducing
unnecessary calculation, improving caching, and generally improving
performance in more complex files
(cfa53e0fbe).
These changes do not affect pure edit mode performance.
Mesh bounding box calculation has been multi-threaded, which can make
exiting edit mode faster
(6a71b2af66).
The accuracy of NURBS knots calculation has been improved, allowing
the combination of Bézier and cyclic modes
(45d038181a).
An new operator on meshes allows converting generic attributes to UV
layers or vertex groups, or other generic data types
(f6888b530a).
The operator also makes it possible to change the domain of an
attribute on original geometry.