The editor and customizer aren’t the only parts of core getting attention.
Felix Arntz has posted about improving the, “well-known, but not well-loved Settings API.” Improvements include a long-desired default callback option for common field types.
Felix also posted about handling the users endpoint in the REST API in a Multisite context.
Also in Multisite land, Jeremy Felt wrote about some of the considerations for a /sites/ endpoint.
