Can't edit transform mode settings after enabling it for content type

Problem/Motivation

Transform mode settings can't be edited once it's used on a content type

Steps to reproduce

1. Go to: /admin/structure/display-modes/transform
2. Create transform mode "Test" and enable it for any content type
3. Click "Edit" button on "Test" transform mode
5. Alternatively, go to /admin/structure/display-modes/transform/manage/node.test to avoid Ajax