How to provide multi step form widget for required file entity fields

I have a file entity with a required field. When I upload a new file, this required field should be filled in immediately. So I came up with the question "How to force user to fill out required fields after media upload" which leads me to the multi-step process.

Those linked issues are all related to Drupal 7. Now I'm wondering, how to accomplish a multi-step form widget for file entities in Drupal 8?

There are only a few widget related options available. I'm able to choose the steps to skip under /admin/config/media/file-settings and nothing else.

So I set "editable file" as field widget for my field, but when I upload a file, the file entity form (modal, no multi-step) is not opened immediately. Furthermore I'm able to submit the node form with an empty required file entity field.

I'm not using any related modules like media or entity browser. Should I, because the built-in file entity widget seems to be depracted? Which widget do I have to use to get a multi-step process which can handle required fields? The build-in widget or some entity browser widget?

I'm lost here and appreciate any help. We should add some documentation about applicable widgets and required field handling.