update: just checked 4.1.2 and found a bunch of new entry points,
Will check the updated code, before posting again here – thanks for pointing me into this direction.
-Elmar

sorry, to be more precise: I changed two files, one for the initial loading, one for immediate update after saving the modal dialog

/config-templatebuilder/avia-template-builder/php/shortcode-template.class.php
in create_sortable_editor_element()

if( $params['args']['disabled'] ) {
	$class .= ' disabled';
}

and in config-templatebuilder/avia-template-builder/assets/js/avia-builder.js
in update_builder_html()

if( values.disabled == 'aviaTBdisabled' ) {
	element_container.addClass('disabled');
}
else {
	element_container.removeClass('disabled');
}

I am looking for a way/trick/hack to safely override these two points.

Hi Victoria,

sure, as a site is work-in-progress one might disable parts of the contents with my small code addition. There will be an additonal checkbox in my setup with “disable this element” if you edit an element. But in the overview you won’t see, if an element is currently disabled or not.
Here I’d like to add a class to the visual builder, if an element has the attribute “disabled” = true

In this case I might render the layout builder like this:
http://www.evernote.com/shard/s2/sh/fee58f4e-0bb3-4de6-b0a9-9c64964cc252/41522809ee6427e12667302385256e55

This will give us a similar functionality to Typo3, having active/inactive elements.
https://docs.typo3.org/typo3cms/EditorsTutorial/singlehtml/_images/PageModuleColumns.png (No. 4)

I’d like the idea in visual composer, where the builder UI shows e.g. the current background image and color as small spots
http://www.evernote.com/shard/s2/sh/92418e73-fb51-49fc-87bd-a3c2397544f5/5b329753997778426fdfbf4897ffc1ee

I would love to add similar extensions to the builder UI based on vaious attributes. But I don’t find an upgrade-safe place to add my code.

I hope this is more clearly.
Thanks
-Elmar