Yes - there is a known issue with the thermal bonding compound in the 7700K (quantity and fill I believe since folks who delid and refill are claiming success in mitigating most of this. Firmware will not help - IMO.
Apple could release a firmware to have a better fan curve - instead of going from almost silent fan to OMG LOUD LOUD LOUD. But with Intel's reports that just opening a website causes the CPU to spike 30 degrees Celsius is normal, maybe it cannot be managed.
As I said, I expected the i7 to run HOT and LOUD. I am fine with that. I was used to my 2010 Macbook Pro running at almost 110 degrees Celsius almost constantly while I was working. I have not heard of reports that the iMac gets too hot and turns off. So it is still within the thermal limits.