[question] what is the correct way to MOVE a subtree of Nodes to elsewhere in the scene graph?

Does anyone have any advice/short example on how to MOVE a subtree of nodes?
#489 is my solution to the removal problem, but what if I want to re-mount that subtree elsewhere after dismounting? My #489 solution completely destroys the dismounted tree structure.

This dismounting problem needs some attention, see: #487, #484, #436, #406, #330, #443, #453.

And even when one gets it right, this then happens:#245