Mura: How to add a validation method to a custom form that doesn't override Mura's async form submission

mura-custom-form.cfm

<!--- Vanilla js --->
<script>
Mura(function(m) {
    window.customFormValidation = function(theform) {
        // example validation
        if (theform.somefield.value === '') {
            alert('Please enter a value in somefield');
            theform.somefield.focus();
            return false;
        }

        // let Mura process the form now
        Mura.submitForm(theform);
        return false;
    }
});
</script>

<form method="post" name="someform" onsubmit="window.customFormValidation(this);return false;" novalidate>
    <input name="somefield" />
    <input name="submit" type="submit" value="Submit" />
</form>


<!--- Example using jQuery Validation --->
<cfif len(m.event('name'))>
	<!--- Do stuff with submitted data --->
	<h3>Thanks!</h3>
<cfelse>
    <script>
    Mura(function(){
        //if jquery.validate is already loaded you don't need to wrap it in a Mura.loader() method
		Mura.loader().loadjs(
			'https://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.17.0/jquery.validate.js',
			function(){
				$('#myform').validate({
					submitHandler:function(frm){
						Mura.submitForm(frm);
					}
				});
			}
		);
	})
	</script>
	<h3>Example Form</h3>
	<form id="myform" data-autowire=true onsubmit="return false;">
	name<br/>
	<input id="name" name="name" type="text" minlength="2" required><br/>
	<button type="submit">submit</button>
	</form>
</cfif>