That should certainly work. Python always allows you to completely redefine any variable, so when you reassign self.coll_node and self.back_node, it’s completely irrelevant what values they had before.
In my code these are actually geomNodes, but they do not get deleted when this function is called…I then write the new geomData, but then both meshes are being rendered.
edit: I found the problem, I was forgetting to release the nodes from the list of all the geomnodes I created for testing purposes