As I've always understood it the sole reason for generating HTML for all fields on a form was to make them available to JavaScript — be it either to read or write values.

Whatever the reasoning I've never liked it, never used it and always disabled it straightaway on any Form I've inherited. To me it causes as many problems as it solves and just seems a little lazy.

There are better ways of making your fields available to JavaScript. For example, we could add this to the Head of the form:

<script type="text/javascript">
    DEXT.Document.Fields = {
        "Name": "Jake Howlett", 
        "Street": "Letsbe Avenue", 
        "County": "Notts", 
        "Phone": "999"
    }
</script>

The web page then has a set of fields it can refer to when needs be. The following function loops them all and alerts their name and value pairings (like "Phone: 999"):

DEXT.Document.listFields = function (){
 for (field in DEXT.Document.Fields) {
  alert(field + ": "+DEXT.Document.Fields[field]);
 }
}

Or you could reference a field directly, like so:

alert('Your name is: ' + DEXT.Document.Fields['Name'])

This approach is a much cleaner way of having field values available in JavaScript. Note that keeping them all inside the DEXT global variable also prevents naming conflicts and is much better than having something like this in your Head:

<script type="text/javascript">
    var Name= "Jake Howlett";
    var Street= "Letsbe Avenue";
    var County= "Notts";
    var Phone= "999";
</script>

That's just bad! Don't do that. It's especially bad in that it creates a global variable called "name". Tut tut.

You don't have to call the global object DEXT. You can call it Acme or HRApp or anything you're confident won't conflict with other variables used.

You can easily generate the JavaScript array of fields like this:

Fields:="Name":"Street":"County":"Phone";
"<script type=\"text/javascript\">"+@NewLine+
" DEXT.Document.Fields={"+@NewLine+
  @Implode("  \""+Fields +"\": \"" +
   @Text(@GetField(Fields)) + "\""; ", ")+
"}"+@NewLine+
"</script>";

Although wouldn't it be nice to be able to choose it on a per-field basis!

You can see a demo of this approach in use here. Change some values in the fields and save the document to see the JavaScript update.