The Cart Items and Cart Total elements are also available with X. What is not available with X is the Header builder.
Unfortunately, We do not have an ETA on when it will be resolved. We are close to releasing a beta for the next release cycle. Our dev team will take a look into this issue, but we can’t guarantee it is something we will be able to fix. There are some issues we’ve seen with plugin integrations not integrating with the AJAX cart.
Meanwhile, the best way you can get a live updating Cart Total is using Pro and adding the “Cart Total” element into your header. It will synchronize anytime a product is added.
I did take a look on your site and it seems it was not heavily customize on the child theme, so it should be fine switching to PRO. However, update to X 9.0.8 and Cornerstone 6.0.8 first, so when you switch latest PRO 5.0.8 there will not be much difference.
Thank you for understanding,