Following your requests, we added a couple of new hooks to the Plugin SDK:
Form Outlets let you customize the area above each record's form. This hook can also be used in "ghost mode" — that is, with no visible UI — to add custom logic to the form in a reliable way (the Record auto-save plugin is a great example of that);
With plugins it is now possible to add custom marks and styles to Structured Text fields!
Here's a sneak peek of the latter feature: