I think there was a list of cocoonJS(canvas+) limitations:
https://www.scirra.com/tutorials/303/ho ... o-cocoonjs
"Compatibility
The following features are not supported in CocoonJS. If any of them are used, Construct 2 will print a message to the debug log saying that they are not supported.
- The form control plugins Textbox and Button are not supported.
- The XML object is not supported.
- The Facebook object is not supported.
- The letterbox fullscreen modes are not supported. If they are selected, it will fall back to 'Scale outer' mode instead.
- The Text plugin's 'Set web font' action is not supported.
- The WebStorage plugin's session storage is not available. Use local storage or global variables instead."
This may not be up to date, due to the fact C2 does not support it anymore (that means C2 will not do specific treatment to make cocoonJS work, AFAIK, it works better than before, but you need to install the open source plugin, see ludei signature for more infos.)
cocoonJS webview and Webview+ are not under the same limitations, but will not run well under iOS 8 and Android 5.
The cocoonJS export is not nessecary, but you can right click in the exporter window to show the deprecated exporters, as of r192, cocoonJS webview, webview+, crosswalk, phonegap, and other cordova exports should use the "Cordova" exporter If I believe the release note.