How inter-object references are handled during copy/paste
If copy/pasting objects with cross dependencies or linkages between them (eg: Portal A and Portal B selected, Portal A has a jump to somewhere in Portal B) and you want the linkages to be updated to point to the new (copied) targets, you MUST paste the objects into a different subsystem to the objects originally copied. Otherwise the copies will point to the original targets.
References WITHIN the one portal are always updated to point to the copied objects within the copied portal
You can do copies in two steps to achieve separately interlinked systems on the same screen by pasting into a temporary portal then copy/pasting back.
Multiple objects can be carried between models. However, if you want inter-object references to point to the copies, put the objects into a subsystem and then carry across the portal. If you carry the objects as individual multiple selections, any linkages between them will be lost.
idkbase note 132