I assumed simply running :XML_CLOSE after making changes to the open XML DOM would do the trick, but apparently this is not the case. Upon closer inspection, I see that the documentation makes this limitation clear:
Please note that only the element stored in the memory will be changed. The Documentation tab is not affected by this.
The element is only stored in the memory using the script function. The Documentation tab is not affected by this.
So what’s the trick? How does one save changes to an XML DOCU tab?