One way of doing verification on your logic in "build" mode is to use querystring parameters to render you MSCRM gui/logic different.
//Place in onload of entity
if (GetItemFromQueryString("tester") == "yes")
document.title = "Entity in TESTER mode [" + JS_VERSION + "]";
else
{
//Hidden fields logic or something else
}
function GetItemFromQueryString(name)
var regexS = "[\\?&]" + name + "=([^&#]*)";
var regex = new RegExp(regexS);
var tmpURL = window.location.href;
var results = regex.exec(tmpURL);
if (results == null)
return "";
return results[1];