IDs visible on refresh/save etc.

The delay happens because the IDs are hidden using JavaScript, after the page is loaded. The widgets use the same code as core, just with a shim so that the JS can identify them. I don’t know how ajax can help here (although I’m more a backend developer).

With JavaScript disabled the widgets would default to the core behaviour, so the editor would still be able to find out the IDs if they wanted to.

There’s already an issue to have something similar in core ( https://www.drupal.org/project/drupal/issues/2881892 🐛 UX: Hide entity ID in autocomplete widget Needs work ). From what I understand, that will remove the IDs in PHP. But that issue has been ongoing for 6 years — hence the module.