Add/improve documentation to have a better developer experience.
Something that I have struggled a lot with is setting up “CORS” for decoupled applications.
The main issue seems to be lack of clear instruction. Organic search for CORS (in search engines) takes you to https://www.drupal.org/project/cors which redirects you towards https://www.drupal.org/node/2715637. There are lots of information in the “comments” section in that change records.
Further References: