Currently, to customize a field a snippet is required.  Not sure of the viability of this idea but throwing it out there to see if it sticks…

Would be nice to be able to create a custom field renderer similar to the way you can create a custom component.  You could then choose it from the page builder and it would add a tab (or something similar) with custom properties, etc.

Use Case
There are several “stock” custom renders that I’ve built for the framework I am working on.  For each field that requires one of these renderers, the personal building the page must choose “custom snippet” and then write a snippet for each field.  The snippet is essentially one line of code for each of the fields, the only difference is the properties passed to the custom renderer.  By offering the ability in the page builder to choose “Custom Renderer” and pick from the registered renderers, the person building the page could specify the properties required to provide to the renderer via the declarative interface and avoid having to write a snippet.  Not only does this simplify page development but also has some performance benefits because the page size decreases.

Food for thought.  Thanks!