Hello, we have an SugarCRM with a lot of custom modules, many of which where created using the module builder.

As we progress we have more customizations, and I personally need to work a lot throughout the code.
One thing I noticed was that

custom/Extension/modules/relationships/

seems to have a lot of duplicate metadata, but that does not seem to be picked up on change/repair-rebuild.

I have started to delete these, since the same metadata is in custom/{Extension}/modules/<modulename>, and perhaps this is some modulebuilder artefact we do not need.
(I thought it was some kind of cruft. And since these are mostly new modules, eventually all or most of this custom/* should move to module/* so we have a reasonably clean sheet to perform per-client customizations on.)

But I still have this nagging feeling it was not by chance the duplicates where created, and may have some actual purpose. Would anyone like to explain that file tree? I cannot seem to find anything meaningful searching for it in the manual or here at the forum. TIA!