Indeed it would make perfect sense to make those shortcodes more visible in the Editor.

But I am thinking: especially for Custom Fields, if the Editor shows a huge block like that we have to make sure that it displays nicely... for example if {field 11} is put

• in the middle of a sentence
• in a table
• etc

So in practice, I would probably not go for

• width: 100%
• and such a big padding

But conceptually, making more visible is a nice improvement.

One thought also about inserting the Title of the Module / Custom Field in the shortcode. What if the Module / Custom Fields has its Title changed / edited after the insertion in that Editor ?

• would it be dynamically changed in that Editor?
• or would it stay with its old Title?

for now I am only go to deal with modules and leacve fields to a later date

If the title is changed after insertion it will not update in the editor as its not a dynamic relationship. Note that if you delete a module you have the same problem already