cache.js

(function(){
    var base = "https://data.schemaapp.com/" + __schemaConfig.accountId + "/";

    var url = __schemaConfig.strip_query ? btoa(unescape(window.location.href.replace(window.location.search, ""))).replace(/=/g, "") : btoa(unescape(window.location.href)).replace(/=/g, "");

    var xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function() {
        if (xhr.readyState === 4 && xhr.status === 200) {
            if (xhr.responseText !== "") {
                var ld = document.createElement('script');
                ld.type = "application/ld+json";
                ld.innerHTML = xhr.responseText;
                document.getElementsByTagName('head')[0].appendChild(ld); 
            }
        }
    }

    xhr.open("GET", base + url, true);
    xhr.setRequestHeader("x-api-key", __schemaConfig.apiKey);
    xhr.send();
})();

<script>
    var __schemaConfig = __schemaConfig || {};
    __schemaConfig.accountId = "{{ $accountId }}";
    __schemaConfig.apiKey = "{{ $apiKey }}";
    __schemaConfig.strip_query = true; // only if strip


    (function() {
        var js = document.createElement('script');
        js.type = "text/javascript"; js.async = true;
        js.src="//cdn.schemaapp.com/javascript/cache.js";
        var f = document.getElementsByTagName("script")[0];
        f.parentNode.insertBefore(js, f);
    })();
</script>

I did something similar to this as a toy app last year. Sent you an invite as a collaborator if you'd like to inspect the code.
https://github.com/JohnM-729/foldout

It's a proof-of-concept that will remote load and invoke a vue app on a page when the user presses alt-shift-f.
Basically a similar approach to what you've got here, create a script node, set the source, and insert it, with the added frills of an event listener and interval to make sure that the vue library from cdn is loaded before invoking the app.

• What you've got above look like it should work fine, however, I would replace the deprecated unescape function with decodeURI.

Also, don't forget that you can use eval() if you need to run a string as if it were JS code, if all else fails and you just want to run something and damn the torpedoes...