This article explains the correct way of adding custom user lists to the global attributes lists at /root/world.
If you wish to add a list of global attributes to the globals attribute at /root/world, the correct way is by using an attribute path like globals.itemLists.myAttrList for the custom attribute list. This convention ensures that the lists will be correctly merged across inputs by the Merge node, and recognized in globals.
Here is an example of how a user global attribute list should look:
NOTE: If you do not use this format, the attribute lists may not be merged correctly and you will only keep one input downstream of the Merge node.