@Arsh_Tyagi , you are not using my code in the right place. The single node I provided replaces all of your IF nodes. It becomes just this up to Spreadsheet node.
Mind you the Set3 node had no data pined to test (at least it is empty for me) but I’m confident that it should work (unless I still do not follow your initial requirement). All your set nodes should be in a single Set (“Flatten data”) combining all the properties (I left that part for you to complete).
We can come to the reset of your questions later as those seem to be a different topic from your original question.