Replacing solder with thermal paste? Thermal paste has always been the preferred conductor between CPUs and heatsinks. Since 486DX2 days. Unless I'm mistaken, what do you mean?
> Intel has also long preached the perils of solder TIM, which can lead to shorter lifespans due to microcracks in the solder TIM that form during heat-induced expansion and contraction.
It's not just about "cheaper solution". Yes, solder will be best for an overclock but that's not the primary objective here.
As they say, good engineering is about optimal tradeoff between every aspect of your product. That includes cost (directly, we are responsible for it) and customer happiness (indirectly, since in a giant company, that gets handed off to the Marketing/PR team). These can get out of sync.
Here is some public information about PTIM: https://patents.google.com/patent/US20150279762A1/en