What about JSON5 style for JSON5.stringify() in Espruino?

Yes, text in json will not be covered ....

ok so let's sum it up

var json = {a:"1",b:2};
data = E.toJS(json);    // {a:\"1\",b:2}"
j = eval('('+data+')');  // {  a: "1", b: 2 }

So, JSON5 is possible on Espruino devices - thanks.