As noted above we switched to the socket rocket based advanced-websocket and it's been meeting our needs so far.

We have worked around the issue for now buy switching to cordova-plugin-advanced-websocket which uses socket rocket internally and at least doesn't appear to trigger the same platform code we think has the bug in it.

My feedbackID is: FB9631338 . I filed it against WebKit but this could be an issue deeper in the platform.