With formatversion=2, we can make some useful changes:

• Return booleans as boolean true instead of empty-string. Where appropriate,[1] return boolean false instead of omitting the property.
• Return empty objects in JSON as {}, rather than [].
• Have action=query's "pages" be an array, instead of an object with page ids as keys that can be difficult to iterate.
• Provide useful property names instead of '*'.
• Eliminate useless indirection, e.g. {"text":"..."} instead of {"text":{"*":"..."}} and {"key1":"value1","key2":"value2"} instead of [{"name":"key1","*":"value1"},{"name":"key2","*":"value2"}].