A set of usability improvements, both on the editorial side and on the development side:
custom locales: you can now add whatever locale you want, just type it out and if it doesn't exist, it will be created for you! No more limits here
if you have more than 5 items in a dropdown, we'll let you search in there:
now also fields can be duplicated. This is particularly useful if you have complex fields with lots of validations (say modular blocks, links, etc) that you need to duplicate with some sligth variations
last but not least, we've add a new parameter when getting a record:
nested=true. If you add that, you'll get the modular blocks inlined in the record response and not as IDs that then will need another call to retrieve the content. Read in the documentation all the details and see an example.