I didn\'t find a lot of instruction setting up crosswalk for iOS it seems like it should be as simple as:
cordova plugin add cordova-plugin-crosswalk-webview
A review of the plugin repository does NOT indicate a cordova-plugin-crosswalk-webview that supports iOS. This means crosswalk does not work as a plugin for iOS.
Yes there is support for Crosswalk for iOS, but you must install via the github repository or other means.
FWIW: there is a WkWebview plugin
UPDATE: 2016-03-19. The follow post was made on February 16, 2016:
Plugins From Git Repositories Are Now Available on PhoneGap Build!