Get Allowed Image Scale from Registry, Change TinyMCE pattern.js

I would like add an AjaxCall to pattern.js in plone.mockup to get the AllowedImageScales from Registry for the Configuration in the TinyMCE Editor.
I have clone the mockup Package to my Filesystem an change the pattern.js File with the relevant Code to reach the goal. But if i recompile the plone-logged-in Bundle in the Resource-Registry, i get the following Error in the ModalDialog:
http://demo.plone.local/++plone++static/plone-logged-in.less: Error: 'http://demo.plone.local/++resource++mockupless/patterns/tooltip/pattern.tooltip.less?bust=1488534953351' wasn't found (404)

I think it is an incorrect use of me. Is this the wrong way? But I have no Idea what is the right way to change the pattern and recompile the plone-logged-in bundle. Can anyone help me with a starting idea? Or is this a part of "evil story" of the resource registry, from which one can always read in the Forum.

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