Someone should review the FIXME's in MobileFrontend associated with API and see if adding the API parameter formatversion=2 fixes any of them.
Gruntfile x ~/git/core/extensions/MobileFrontend $ ag 'FIXME.*API'
67: FIXME: MediaWiki API, seriously?
73: FIXME: API - missing is set to empty string (face palm)
183: // FIXME: AbuseFilter should have more consistent API responses
76: FIXME: [API] have to request timestamp since api returns an object
96: FIXME [API] a lot of duplication follows due to the silly way generators work
116: FIXME: [API] in an ideal world imageData would be a sorted array
124: FIXME: API I hate you.
144: FIXME: API bug 48512
153: FIXME: API returns object when array would make much sense
253: // FIXME: API doesn't return this information on duplicate images...
54: // FIXME: API
148: FIXME: [API] the API sometimes returns an object and sometimes an array
211: FIXME: API returns an object when a list makes much more sense
215: // FIXME: "|| " wouldn't be needed if API was more consistent