In 3.3 and earlier versions, the editor illustrated quite well when text was formatted with custom styles ( both inline and block ). See attached 3.3_customstyles.PNG

Actuall behaviour : With the same text and formatting in 4.3, the editor doesn't illustrate  the inline custom style at all. The block style is only illustrated as such when you place the cursor on it and can see the highlighted_block tag below the edit input field.... (see 4.3_customstyles.PNG)

Expected:

The formatting should be illustrated in the editor too, similar to what is happening in 3.x