We've been working on updating the wkwebview plugin to address many of the issues it has had.
The latest version, 3.0, includes a bunch of fixes regarding CORs issues, background issues, and much more.
Give it a try and let us know how it works for you!
If you already have the wkwebview plugin installed, you'll want to remove it first.
ionic plugin rm cordova-plugin-wkwebview-engine --save
Then install the latest from master
ionic plugin install https://github.com/driftyco/cordova-plugin-wkwebview-engine --save
We're still looking for feed back on things like remote/local audio/video, integration with custom URL schemes, and different href schemes.
If you come across any problems, please feel free to open on issue on the plugin repo.
If you want to know more about the WKWebView plugin and its benefits, please read our previous blog: http://blog.ionic.io/cordova-ios-performance-improvements-drop-in-speed-with-wkwebview/