Consider using the original regexp, which doesn't require keys to be quoted, and parsing the JSON using Cpanel::JSON::XS and turning relaxed mode.

Javascript objects can of course still include values which cannot be encoded into JSON, for example:

var obj = {
  "some_key": Date.now(),
  "other_key": function () {
    console.log("Hello world");
  }
};
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So if your Javascript objects contain things like this, you'll be out of luck. You might want to wrap your JSON decoding in try/catch or eval.