Good. To summarize your position, you are suggesting that ???? ??? only applies when the top object actually becomes hot. Correct?
In addition to the Aruch HaShulchan you quoted, this is also the view of the Da’as Kedoshim 91:4, andclearlyy implied in the Yam Shel Shlomo 7:45 and many other Achronim.
Now if ???? ??? is primarily a ??????, what would say to this follow-up.
What if the top item was the hot one, and we clearly see that it significantly warmed the bottom one, maybe even reaching ?? ??????